Jepsen, G.L.; Mayr, E.; Simpson, G.G. 1949. Genetics, paleontology and evolution. Princeton, University Press. pp. i-xv, 1-474.
Simpson, G.G. 1945. The principles of classification and a classification of mammals [suborder Ceratomorpha]. Bulletin of the American Museum of Natural History, New York 85: 14-17+139-143+163+252-253+256-258.






