List of academic databases and search engines

This article contains a representative list of notable databases and search engines useful in an academic setting for finding and accessing articles in academic journals, institutional repositories, archives, or other collections of scientific and other articles. Databases and search engines differ substantially in terms of coverage and retrieval qualities.[1] Users need to account for qualities and limitations of databases and search engines, especially those searching systematically for records such as in systematic reviews or meta-analyses.[2] As the distinction between a database and a search engine is unclear for these complex document retrieval systems, see:

  • the general list of search engines for all-purpose search engines that can be used for academic purposes
  • the article about bibliographic databases for information about databases giving bibliographic information about finding books and journal articles.

The terms "free", "subscription", and "free & subscription" will refer to the availability of the website as well as the journal articles used. Furthermore, some programs are only partly free (for example, accessing abstracts or a small number of items), whereas complete access is prohibited (login or institutional subscription required).

The "Size" column denotes the number of documents (articles, publications, datasets, preprints) rather than the number of citations or references. The database itself should be the primary source of statistics, and if it is not accessible, the independent estimates released as journal papers should be. Notably, Google Scholar does not offer such detail, but the database's size has been calculated.[2]

Operating services

Full-text aggregators

The main academic full-text databases are open archives or link-resolution services, although others operate under different models such as mirroring or hybrid publishers. Such services typically provide access to full text and full-text search, but also metadata about items for which no full text is available.

This list focuses on general-purpose services; OpenDOAR can be used to find thousands of open-access repositories. The table is sorted by the number of works for which full-text is made available.

NameDiscipline(s)Size (full-texts)DescriptionAccess costOpen dataProvider(s)
Internet Archive ScholarMultidisciplinary25,000,000Focus on fulltext search of open access journals and conference proceedingsFreeYesInternet Archive
CORE[3]Multidisciplinary9,800,000[4] (207,000,000 metadata[5])A full text aggregator of all open access papers from repositories (institutional, subject, preprints, etc.) and journals. Around 20 million monthly active users.FreeNo[4]Open University
CiteSeerX[6]Multidisciplinary8,401,126Replaced CiteSeer, and ChemXSeer. Mainly Computer science, Statistics, Mathematics.FreeSemi-free[7]Pennsylvania State University
Paperity[8]Multidisciplinary10,500,000Full-text aggregator of open access journals and papers (>17,000 journals) from all academic disciplines.FreeNo[9]Paperity Sp. z o.o.
Semantic ScholarMultidisciplinary8,100,000[10] (200,000,000 metadata[11])Mostly computer science and biomedical publications. Powered by semantic analysis.FreeSemi-free[10]Allen Institute for Artificial Intelligence
Europe PMC[12]Biomedical7,500,000 (39,000,000 metadata)Abstracts & full text ( 7.5 million) biomedical and life sciences articles (Dec 2020). Includes text mining tools and links to external molecular and medical data sets.FreeYesEMBL-EBI
PubMed Central (PMC)[13]Biomedical, life sciences7,500,000Free full-text archive of publications and preprintsFreeYesNIH, NLM
ResearchGateMultidisciplinary4,000,000[citation needed]Commercial social networking site for scientists and researchers. Over 19 million registered users that share their articles, datasets and other research output.FreeNoResearchGate GmbH
SSRN: Social Science Research NetworkSocial science950,733Research papers from more than 55 disciplinesFree & SubscriptionNoElsevier
HALMultidisciplinary760,000 (2,000,000 metadata)[14]An open-access database for French researchers. Organized into institution and domain portals.FreeYesCNRS's Centre pour la Communication Scientifique Directe (CCSD)
RePEc: Research Papers in Economics[15]Economics90,000 (3,200,000 metadata)[16]Working papers, journal articles, books, books chapters and software components (including 1.2 million full-text articles)FreeIDEAS: Federal Reserve Bank of St. Louis

EconPapers: Örebro University School of Business

PhilPapersPhilosophy70,000[17] (2,540,317 metadata)Index journals, books, open access archives, and personal pages maintained by academicsFreePhilPapers
ERIC: Educational Resource Information Center[18]EducationUnknown (1,500,000 metadata)Education literature and resources dating back to 1966.Free & SubscriptionUnited States Department of Education (available by subscription from OCLC, CSA)
Synthical[19]Multidisciplinary3,000,000[20]Pre-prints, mainly computer science, mathematics, statistics, chemistry, and biology.FreeYesSynthical
Zendy[21]MultidisciplinaryUnknown (31,266,280 [22]Focus on scholarly content including full-text papers, conference proceedings, indexed journals, books, and book chapters from open access sources. Content is available in 38 languages, covering various subjects and disciplines.Free & SubscriptionYesKnowledge E, Zendy

Metadata services

NameDiscipline(s)SizeDescriptionAccess costProvider(s)
AGRIS: Agricultural database[23]Agriculture12,021,578Covers agriculture, forestry, animal husbandry, aquatic sciences and fisheries, human nutrition, extension literature from over 100 countries. Indexes unpublished scientific and technical reports, theses, conference papers, government publications.FreeFAO
Arachne[24]Archaeology, Art history4,485,5342.4 million digital images from archive material, 1 million of books, 40,000 high quality scans of ancient sculptures, 300 volumes of ancient books with more than 60,000 pagesFreeDAI & University of Cologne
AMiner[25]Computer Science265,034,285Online service used to index and search academic social networksFreeTsinghua University
Arts & Humanities Citation Index[26]Arts, Humanities4,900,000Part of Web of Science. 1,800 journals across 28 arts & humanities disciplines. Records back from 1975 to present.SubscriptionClarivate Analytics
Astrophysics Data System[27]Astrophysics, Geophysics, Physics13,300,000Publications in Astronomy and Astrophysics, Physics, and the arXiv e-printsFreeHarvard University
ATLA Religion Database[28]Religious studies3,000,000Provides information on topics such as biblical studies, world religions, church history, and religion in social issuesSubscriptionEBSCO Publishing
BASE: Bielefeld Academic Search Engine[29]Multidisciplinary259,497,239Metadata for 260 million documents from more than 8,000 content providersFreeBielefeld University
Book Review Index OnlineBook reviews5,600,000Reviews of periodicals and books – including those on tape and electronic mediaSubscriptionThomson Gale
Books in PrintBooks2,500,000Reviews covering over 2.5 million titlesSubscriptionR. R. Bowker
CAB AbstractsApplied life sciences10,000,000Bibliographic information service providing access to applied life sciences literature.SubscriptionCABI
CINAHL: Cumulative Index to Nursing and Allied Health[30]Nursing, Allied Health7,800,000Journal articles about nursing, allied health, biomedicine and healthcare. Covers 5,500 journals (English and other language).SubscriptionEBSCO
CiNii[31]Multidisciplinary22,000,000Database of articles in the Japanese language from 3600 journalsFree & SubscriptionNational Institute of Informatics
CNKIMultidisciplinary160,000,000A Chinese bibliographic databaseFree & SubscriptionCNKI
CORE[3]Multidisciplinary207,000,000[5]Around 20 million monthly active users.FreeOpen University
Crossref[32]Multidisciplinary111,231,936An official Digital Object Identifier (DOI) Registration Agency of the International DOI Foundation. Metadata about publications, datasets, grants, preprints from 17,633 members (journals, publishers, etc.)FreeCrossref
DeepDyveMultidisciplinary20,000,000Commercial website that sells access to scientific and scholarly articles from a large range of academic publishers (over 1700 journals). Limited free access.Free & SubscriptionDeepDyve
Dimensions[33]Multidisciplinary302,000,000Publications, books and book chapters, preprints and conference proceedings (linked to data sets, funding, publications, patents, clinical trials, and policy documents). Based on CrossRef. Contains citation-based indicators and Altmetric attention scores.Free & SubscriptionDigital Science & Research Solutions Ltd
Directory of Open Access Journals (DOAJ)[34]Multidisciplinary8,265,735Articles from 18,652 open access journals (Dec 2022)FreeInfrastructure Services for Open Access (IS4OA)
DBLP[35]Computer science5,387,041Comprehensive list of papers from major computer science conferences and journalsFreeLeibniz Center for Informatics and University of Trier
EconBiz[36]Economics10,000,000Covers journals, working papers & conferences in business studies and economicsFreeZBW- German National Library of Economics– Leibniz Information Centre for Economics (ZBW)
EconLit[37]Economics1,600,000Covers articles and other materials dating back to 1969SubscriptionAmerican Economic Association (available from EBSCOhost, ProQuest, OVID, and AEA)
EMBASE[38]Biomedicine, Pharmacology32,000,000Biomedical database with a focus on drug and pharmaceutical research. Rrecords from over 8,500 journals (1947–present).SubscriptionElsevier
FSTA – Food Science and Technology AbstractsFood science, Food technology, Nutrition1,500,000The database of information on food science, food technology and nutritionSubscriptionIFIS Publishing (available via EBSCOhost, IHS Inc., Ovid, Proquest Dialog, STN and Web of Science)
GeoRef[39]Geosciences4,000,000Records from 3,500 journals in 40 languagesSubscriptionAmerican Geosciences Institute
Google Scholar[1]Multidisciplinary389,000,000The biggest academic database & search engine (over 390 million records, unofficial estimate)FreeGoogle
InformitMultidisciplinary8,000,000Australasian aggregator of bibliographic databases and journalsSubscriptionRMIT Training Pty Ltd (RMIT Training)
InspecPhysics, Engineering, Computer Science18,000,000Contains records in physics, electrical engineering, electronics, communications, control engineering, information technology, manufacturing, production, and mechanical engineering.SubscriptionIET
International Nuclear Information System (INIS)[40]Nuclear Physics, Nuclear Energy, Medical Physics4,600,000A leading bibliographic and grey literature repository covering all areas of nuclear science and technology.FreeInternational Atomic Energy Agency
International Philosophical BibliographyPhilosophy1,000,000Focus on the history of philosophy and continental philosophy.SubscriptionUniversité Catholique de Louvain (available from Peeters Publishers)
J-Gate[41]Multidisciplinary71,692,382J-Gate is an electronic gateway to global e-journal literature (articles from 58,000 journals)Free & SubscriptionInformatics India Ltd
The Lens[42]Multidisciplinary228,108,724Serves global patent and scholarly knowledge as a public good to inform science and technology enabled problem solving.Free & SubscriptionCambia
MathSciNetMathematics3,600,000Records from 650 math journals (early 1800–present)SubscriptionAmerican Mathematical Society
MEDLINEMedicine, Healthcare26,000,000Easy-to-use interface to search and retrieve citations and abstracts from 5,200 journals via MeSH vocabularyFreeNLM
MyScienceWorkMultidisciplinary90,000,000Database includes more than 90 million scientific publications and 12 million patents.FreeMyScienceWork Inc
National Diet Library CollectionMultidisciplinary44,187,016Japanese. Catalog for the National Library of Japan.FreeNational Diet Library
OAIster[43]Multidisciplinary30,000,000Covers records contributed by over 1,500 organizationsFreeOCLC
OpenAIRE GraphMultidisciplinary242,000,000Scientific Knowledge Graph aggregating, deduplicating, enriching metadata of publications, research data, research software, and other products, with citations links and links to funders and grants - core service in support of the European Open Science CloudFreeOpenAIRE AMKE (not-for-profit)
OpenAlexMultidisciplinary205,000,000[44]Index and metadata for all scholarly output.FreeOurResearch
PsycINFOPsychology3,700,000Focus at behavioral science and mental health. Coverage 1887–present.SubscriptionAPA
PubMed[45]Biomedical, life sciences30,000,000A database primarily of references and abstracts on life sciences and biomedical topics. Includes MEDLINE, PubMed Central, and Bookshelf.FreeNIH, NLM
RSWBplus[46]Civil Engineering, Architecture1,600,000Bibliographic database for planning and building related publications, chronological coverage since 1975. Focus: German-language publications, journal articles, book chapters, conference papers, research reports.SubscriptionFraunhofer IRB
Russian Science Citation IndexMultidisciplinary35,409,829A bibliographic database of scientific publications in RussianFreeScientific Electronic Library
ScienceOpenMultidisciplinary66,000,000Natural and physical sciences, social sciences, and humanities. Incorporates arXiv, PubMed, and SciELO. Integrated with ORCID Altmetric uids. Articles from >25,000 journals.FreeScienceOpen Inc.
Scopus[47]Multidisciplinary78,000,000Records from over 20,500 titles from over 5,000 international publishersSubscriptionElsevier
Web of Science[47]Multidisciplinary171,000,000Includes other products, such as Social Sciences Citation Index, Science Citation Index, Biological Abstracts & The Zoological RecordSubscriptionClarivate Analytics
Zasshi Kiji Sakuin: Japanese Periodicals IndexMultidisciplinary6,600,000Scholarly articles in JapaneseFree & SubscriptionNational Diet Library
Zentralblatt MATHMathematics4,000,000Mainly reviews and abstracts.FreeFIZ Karlsruhe
The Zoological RecordZoology3,500,000Unofficial register of scientific names & papers in zoology. Coverage 1864–present.SubscriptionClarivate Analytics

Smaller metadata services

Services with less than a million searchable records.

NameDiscipline(s)SizeDescriptionAccess costProvider(s)
Academic Search[48]MultidisciplinarySeveral versions: Complete, Elite, Premier, and Alumni EditionSubscriptionEBSCO Publishing
Aerospace & High Technology DatabaseAerospace, Aeronautics, AstronauticsProvides indexing and abstracts from current serial and non-serial titles, including content from AIAA and NASASubscriptionProQuest
African Journals OnLine (AJOL)[49]Multidisciplinary185,649Scholarly journals published in AfricaFree & SubscriptionAJOL
AgeLine[48]Sociology, GerontologyIncludes information on aging-related topics, including economics, public health and policySubscriptionEBSCO Publishing
AGRICOLA: Agricultural Online Access[50]AgricultureProvides public access to information on agriculture and allied fields (17th century - present)Free & SubscriptionNAL (free access NAL, subscription access ProQuest, OVID)
AiritiMultidisciplinaryChinese e-content provider of Chinese academic e-journals, Taiwanese academic e-journals, classical art imagesSubscriptionAiriti Inc.
Analytical Abstracts[51]Chemistry505,481Selection of analytical chemistry articles published by the Royal Society of Chemistry (around 100 journals)SubscriptionRSC
Anthropological Index Online[52]AnthropologyIndexes only (no abstracts or full-text) the anthropology journals received by The Anthropology Library at The British MuseumFree & SubscriptionRAI
Anthropological Literature[53]Anthropology, Archaeology670,000An index of journals primarily from Tozzer Library, as well as other open-access journals (660 journals with more than 670,000 articles)Free & SubscriptionHarvard University (non-Harvard access provided by OCLC)
ArchiveGridMultidisciplinaryDirectory of archival materials from American and international institutions, including over five million recordsFreeWorldCat
ASCE LibraryCivil Engineering150,000All civil engineering disciplines including structural engineering, geotechnical engineering, transportation engineering, construction engineering, environmental engineering, engineering mechanics, sustainability, water resources, irrigation. hydraulics, hydrology, waterways, urban planning, cold regions ...Free & SubscriptionASCE
AULIMP: Air University Library's Index to Military PeriodicalsMilitary ScienceThe articles, news items, book reviews and editorials from 63 English language military and aeronautical periodicalsFreeAir University
Biological Abstracts[54]BiologyBiomedical research literature published from more than 4,000 journals internationally.SubscriptionThomson Reuters
CabellsMultidisciplinary35,000Database to discover, evaluate, and compare journals. Journal listings include publication info, submission guidelines, and metrics.SubscriptionCabells
Chemical Abstracts ServiceChemistryApproximately 8,000 journals, technical reports, dissertations, conference proceedings, and new booksSubscriptionACS
Chinese Social Sciences Citation Index[55]Social sciences60,000Covers about 500 Chinese academic journals of humanities and social sciencesSubscriptionNanjing University
CHBD: Circumpolar Health Bibliographic Database[56]Medicine7,900Contains records describing publications about all aspects of human health in the circumpolar regionFreeUniversity of Calgary
Civil engineering databaseCivil engineering270,000A bibliographic database covering all of ASCE's publications since 1872FreeAmerican Society of Civil Engineers
Cochrane LibraryMedicine, HealthcareIncludes reviews of research to promote evidence-based healthcare.SubscriptionWiley Interscience
Current ContentsMultidisciplinaryPart of Web of Science. Contains 7 discipline-specific subsets.SubscriptionClarivate Analytics
DSI: Stuttgart_Database_of_Scientific_Illustrators_1450–1950Multidisciplinary13,096bio-bibliographic data about illustrators of published scientific works from c.1450 until 1950 in 100+ countries, with 20 search fieldsFreecompiled by the Section for History of Science & Technology, University_of_Stuttgart
Index Copernicus[57]MultidisciplinaryContains over 2,500 journals (including 700 journals from Poland).FreeIndex Copernicus Ltd
Information Bridge: Department of Energy Scientific and Technical InformationMultidisciplinary266,000Provides free public access to over 266,000 full-text documents and bibliographic citations of Department of Energy (DOE) research report literature. Documents are primarily from 1991 forward.FreeDOE (OSTI)
Indian Citation Index[58]Multidisciplinary860,000Covers articles from 1100+ journals from India from scientific, technical, medical, and social sciencesSubscriptionICI
IARP[59]MultidisciplinaryOpen-access knowledge management system incorporating grants, publications, conferences in natural and social & behavioral sciencesFreeVolunteer Collaboration
INSPIRE-HEPPhysics, (High Energy)An open access digital library for the field of high energy physics (HEP) (operates since the 1970s)FreeCERN, DESY, Fermilab, SLAC and IHEP
International Directory of PhilosophyPhilosophy37,000Contains information on university philosophy departments and programs, philosophical societies, research centers, journals, and philosophy publishers in the U.S., Canada, and approximately 130 other countries.Free & SubscriptionPhilosophy Documentation Center
International Medieval Bibliography[60]Medieval studies440,000A multidisciplinary bibliographic database covering Europe, North Africa and the Middle East for the entire period from AD 300 to 1500SubscriptionLeeds University (available from Brepols Publishers)
JournalSeekMultidisciplinaryCatalogues over 39,000 journals' information (the description, aims, scope, journal abbreviation, journal homepage link, subject category and ISSN).Free & SubscriptionGenamics
JurnMultidisciplinaryIndex property and open access journals in the arts, humanities, ecology, science, biomedical, business and economics.FreeDavid Haden
L'Année philologiqueClassical studiesOver 860,000 bibliographical entries, including keywords, abstracts, and links to the full text.SubscriptionSociété Internationale de Bibliographie Classique (available from Brepols Publishers)
LexisNexisLawElectronic database for legal and public-records related informationSubscriptionReed Elsevier
LingbuzzLinguistics550,000A free archive of linguistics articles, with a focus on syntax, semantics, phonology and morphologyFreeUniversity of Tromsø
LinguamaticsMedicine, Healthcare, PatentsInterface for searching MEDLINE, ClinicalTrials.gov, FDA Drug Labels, PubMed Central, and Patent Abstracts.SubscriptionLinguamatics
LogeionClassical StudiesAn open-access database of Latin and Ancient Greek dictionariesFreeUniversity of Chicago
Mendeley[61]MultidisciplinaryN/ACrowdsourced database of research documents. Over 100M documents uploaded by the researchers plus data from repositories (e.g. PubMed and arXiv)Free & SubscriptionElsevier
National Criminal Justice Reference ServiceCriminology, Sociology225,000Abstracts of scholarly journal articles, agency and NGO reports, audiovisual products, and conference proceedings.FreeUnited States Department of Justice, Office of Justice Programs
OpenGreyGrey literature700,000Indexes European grey literatureFreeInstitut de l'information scientifique et technique
ORCID[62]MultidisciplinaryAn open and independent registry for contributor identification in research and academic publishing. List: biography, education, employment, works, grants, peer-review. Over 9.3 million profiles.FreeORCID Inc.
Philosophy Documentation Center eCollectionApplied ethics, Philosophy, Religious studiesJournals, series, conference proceedings, and other works from several countries onlineFree & SubscriptionPhilosophy Documentation Center
POIESIS: Philosophy Online SerialsPhilosophy, applied ethics, religious studiesJournals and series, online access for institutions with printFree & SubscriptionPhilosophy Documentation Center
Publons[63]MultidisciplinaryService for academics to track their peer review and editorial contributions for academic journals. Merged with ResearcherIDFreeClarivate Analytics
PubPsychPsychology800,000Datasets and offers, where available, full-text linking, links to additional information and link resolvingFreeLeibniz Institute for Psychology Information
Readers' Guide to Periodical LiteratureLiteratureReference guide to articles in >470 periodical magazines and journals, organized by article subject (1890 to present)SubscriptionH. W. Wilson Company
Rock's Backpages[64]Music40,000Primary documents from the history of rock and roll. Articles, including interviews, features and reviews, which covered popular music from blues and soulFree & SubscriptionBackpages Ltd
SafetyLitMultidisciplinary640,000>35 distinct professional disciplines (architecture - zoology) relevant to preventing unintentional injuries, violence, and self-harmFreeSafetyLit Foundation
Science.govMultidisciplinaryA gateway to government science information and research results from over 60 databases, over 2,200 websites, and over 200 million pages.FreeUnited States Government
Science Citation Index[65]MultidisciplinaryPart of Web of Science. 24,000+ journals across 254 subject disciplines.SubscriptionClarivate Analytics
Scientific Information Database (SID)Engineering & Technology, Medical Science, Basic Science, Human SciencesAn Iranian index of academic journals and access to full text or metadataFreeScientific Information Database
SCIndeks - Serbian Citation IndexMultidisciplinary80,000A bibliographic database, a national citation index, an Open Access full-text journal repository and an electronic publishing platform. Articles from >230 journals.FreeCEON/CEES - Centre for Evaluation in Education and Science
SNAC (Social Networks and Archival Contexts)MultidisciplinaryDirectory of archival materials grouped by subject entityFree
Social Sciences Citation IndexSocial sciencePart of Web of ScienceSubscriptionClarivate Analytics
SocolarMultidisciplinaryScholarly open access resources in different language (mainly Chinese)Free & SubscriptionChina Educational Publications Import and Export Corporation
Ulrich's Periodicals DirectoryMultidisciplinary336,000Provides serials for periodicalsSubscriptionProQuest
VET-BibSocial Science, Education80,000European vocational education and training (VET) literatureFreeCedefop
WestLawLawOver 40,000 databases of case law, state and federal statutes, administrative codes, newspaper and magazine articles, public records, law journals, law reviews, treatises, legal forms and other information resourcesSubscriptionThomson Reuters
WorldCat[66]MultidisciplinaryUnified catalog of member libraries' catalogsFree & SubscriptionOCLC Inc.
WorldWideScienceMultidisciplinaryA union catalog that itemizes the collections of 17,900 libraries in 123 countriesFree & SubscriptionDOE (OSTI)

Publishers

Content by most academic publishers is indexed by CrossRef, DOAJ and/or DataCite. Some publishers are also listed separately in the table below.

NameDiscipline(s)SizeDescriptionAccess costProvider(s)
Association for Computing Machinery Digital LibraryComputer Science, Engineering2,892,573Collection of all ACM publications, including journals, conference proceedings, technical magazines, newsletters and booksSubscriptionAssociation for Computing Machinery
Analytical Sciences Digital Library[67]Analytical chemistryA collection of peer-reviewed electronic resources on chemical measurements and instrumentationFreeNSDL and ACS
Bibliographie de civilisation médiévaleMedieval studiesA bibliography of monographs on the Middle Ages. As of 2018, it contains about 65,000 fully classified bibliographic records.SubscriptionUniversity of Poitiers (available from Brepols Publishers)
BioOneBiology, Ecology, Environmental ScienceFull-text from >180 scientific journals in Biodiversity Conservation, Biology, Ecology, Environmental Science, Entomology, Ornithology, Plant Science, and Zoology.Free & SubscriptionBioOne
IEEE XploreComputer Science, Engineering, Electronics5,360,654Over 5 million records.SubscriptionIEEE
IngentaConnectMultidisciplinary5,000,000Covers articles from 13,000 journalsFree & SubscriptionIngenta
JSTOR: Journal StorageMultidisciplinary12,000,000Journal articles, books, and primary sources in 75 disciplines (1870–present)Free & SubscriptionJSTOR
OpenEdition.orgHumanities, social science60,000Offers four international-scale publication and information platforms in the humanities and social sciences (10,661 books, 549 journals, 3793 blogs, 45,591 events).FreeCléo (UMS 3287) CNRS EHESS University of Avignon
Project MUSEHumanities, social scienceMUSE's online journal collections are available on a subscription basis to academic, public, special, and school libraries. More than 2,500 libraries worldwide subscribe.SubscriptionProject MUSE, Johns Hopkins University Press
SciELOMultidisciplinary573,525Database and a model for cooperative electronic publishing in developing countries (mostly South America and Africa). Indexes >1700 journals.FreeFAPESP, CNPq and BIREME
ScienceDirectScience including Medicine18,000,000Content from more than 4,000 academic journals and 30,000 e-booksSubscriptionElsevier
SpringerLinkMultidisciplinary13,859,779Journals, books, series, protocols, reference works and proceedingsFree & SubscriptionSpringer

Services no longer operating

The following services are no longer operating; this may be because they were not updated, abandoned entirely, replaced by other, etc.

NameDiscipline(s)DescriptionAccess costProvider(s)
Bioinformatic HarvesterBiology, BioinformaticsA meta search engine for 50 major bioinformatic databases and projects. Project appears to be not available anymore.FreeLiebel-Lab KIT from Karlsruhe Institute of Technology
citeULikeComputer scienceNot available. Ceased operations as of March 30, 2019FreeOversity Ltd.
ChemXSeerChemistryThe project seems abandoned in 2018FreePennsylvania State University
citebase SearchMathematics, Computer science, PhysicsSemi-autonomous citation index of free online research. Not available; ceased operations in 2013FreeUniversity of Southampton
citeSeerComputer ScienceReplaced by citeSeerX.FreePennsylvania State University
Chemisches Zentralblatt Structural DatabaseScience, ChemistryWeb-based retrieval application that provided language-independent access to the information contained in Chemisches ZentralblattSubscriptionInfoChem
CogPrints: Cognitive Sciences Eprint ArchiveMultidisciplinaryAn electronic archive for self-archive papers in Psychology, Neuroscience, Linguistics, Computer Science, Philosophy, Biology, and Medicine. Contains over 2000 free articles. Not updated since 2017.FreeUniversity of Southampton
The Collection of Computer Science BibliographiesComputer scienceOne of the oldest (if not the oldest) bibliography collections freely accessible on the Internet (founded 1993). Contains 4.2 million records. Not updated since 2017.FreeAlf-Christian Achilles
Current Index to StatisticsStatisticsLimited free search. Not updated since 2017.SubscriptionAmerican Statistical Association and the Institute of Mathematical Statistics
Ei CompendexEngineeringElectronic version of Engineering IndexSubscriptionElsevier
GENESISWomen's historyDescriptions of women's history collections from sources in the UK, as well as women's history websites.FreeLondon Metropolitan University
Global Health[68]Public HealthSpecialist abstracting and indexing database dedicated to public health research and practice. Contains scientific records from 1973 to the present.SubscriptionCABI
HCI BibliographyHuman–computer interfaceAn electronic bibliography for most of HCI for researchers, developers, educators, and students. Over 126,000 publications. Not updated since 2018.FreeGary Perlman
International Bibliography of Humanism and the RenaissanceRenaissance studiesA bibliography of academic publications on European culture and history in the 16th and 17th centuries. It seems that the database is not available and not updated since 2013.SubscriptionBrepols Publishers
Meteorological and Geoastrophysical AbstractsMeteorology, Astrophysics, GeologyOver 508,379 records from 654 journals. It seems that the database is not available and not updated since 2009.SubscriptionAmerican Meteorological Society (available from Dialog and CSA).
Microsoft Academic[69]MultidisciplinaryCovered publications from over 49,000 journals. Retired on December 31, 2021.[70]FreeMicrosoft
Philosophy Research IndexPhilosophyIndex of books, journals, dissertations, and other documents. Merged with PhilPapers.SubscriptionPhilosophy Documentation Center
POPLINEPopulation, Family PlanningA collection of population, family planning and related reproductive health and development literature. Retired in 2019.FreeKnowledge for Health, Center for Communication Programs, JHSPH
Questia: Online Research LibraryMultidisciplinaryEmphasis on books and journal articles in the humanities and social sciences. Closed down on December 21, 2020SubscriptionQuestia
Science AcceleratorMultidisciplinaryA gateway to results of DOE research and development and major R&D accomplishments of interest to DOE. Not working from 2014FreeDOE
SparrhoMultidisciplinaryResearch articles and patents from 45k+ journals and preprint servers. Uses content recommendation concept.SubscriptionDistylled Ltd.

See also

References