Gerrit Davidse, Mario Sousa Sánchez, Sandra Knapp, A. O. Chater, Fernando Chiang-Cabrera Flora mesoamericana. Publicado por Universidad Nacional Autónoma de México, Instituto de Biología, 1994 ISBN 968-36-3309-9
Peralta Knapp & Spooner. Taxonomy of Wild Tomatoes and Their Relatives ISBN 0-912861-84-3
Knapp and Mallet ECOLOGY: Refuting Refugia? Science 71 DOI:10.1126/science.1083007
Katherine J. Willis, Lindsey Gillson, and Sandra Knapp 2007. Biodiversity hotspots through time: an introduction Phil. Trans. R. Soc. B 362, 169–174