1. Abel, O. 1931. Die Stellung des Menschen im Rahmen der Wirbeltiere, G. Fisher, Jena.
2. Andrews, P. 1970. Two new fossil primates from the Lower Miocene of Kenya. Nature (Lond.) 288: 537–540.
3. Andrews, P. 1978. A revision of the Miocene Hominoidea of East Africa. Bull. Br. Mus. (Nat. Hist.) Geol. 30 (2): 85–244.
4. Andrews, P. 1981. Species diversity and diet in monkeys and apes during the Miocene, in: Aspects of Human Evolution ( C. Stringer, ed.), pp. 25–62, Taylor and Francis, London.
5. Cartmill, M., MacPhee, R. D. E., and Simons, E. L. 1981. Anatomy of the temporal bone in early anthropoids, with remarks on the problem of anthropoid affinities. Am. J. Phys. Anthropol. 56: 3–21.