1. and 1970 Baboon Ecology. Bibliotheca Primatologica 12.
2. Observations on the teeth of the mountain gorilla (Gorilla gorilla beringei)
3. 1963 Observations of the ecology of some large African mammals. In: African Ecology and Human Evolution. and , eds. Aldine, Chicago, pp. 43–54.
4. New Finds at the Swartkrans Australopithecine Site