1. Clark, W. E. Le Gros, The Fossil Evidence for Human Evolution (University of Chicago Press, 1955).
2. Vallois, H. V., and Movius, jun., H. L. (eds.), Catalogue des Hommes Fossiles (CR Cong. Géol. Intern., Algiers, 1952).
3. Clarke, M. R. B., and Maxwell, A. E., Program Specification PS 17 EXCHLF SSP 1 (Univ. London Inst. Computer Sci., 1966).
4. Musgrave, J. H., thesis Univ. Cambridge (1970).
5. Boule, M., Annls. Paléontol., 6, 7 and 8 (1911–1913).