Crompton, A. W., 1968, The enigma of the evolution of mammals: Optima, v. 18, p.
137-151.
Gingerich, P. D., 1977, Patterns of Evolution in the Mammalian Fossil Record,
in Hallam, A., ed., Patterns of Evolution as Illustrated by the Fossil
Record: Amsterdam, Elsevier, p. 469-500.
Huxley, T. H., 1880, On the application of the laws of evolution to the
arrangement of the Vertebrata, and more particularly of the Mammalia:
Proceedings of the Zoological Society of London, v. 43, p. 649-661.
