1. Broom, R.: Mammal-like reptiles of South America. London: H.F. & G. Witherby 1932.
2. Colbert, E.H.: The Dinosaur book, 2nd ed. New York: McGraw-Hill Book Co. 1951.
3. — Evolution of the vertebrates. Science Edition. New York: John Wiley & Sons, Inc. 1955.
4. Heilmann, G.: The origin of birds. New York: D. Appleton & Co. 1927.
5. le Gros Clark, W.E.: The crucial evidence for human evolution. Proc. Am. Phil. Soc. 103, 159–172 (1959).