1. Albrecht, H., and Dunnett, S. C. (1971).Chimpanzees in Western Africa, Piper, München.
2. Baldwin, P. J. (1979).The Natural History of the Chimpanzee (Pan troglodytes verus)at Mt. Assirik, Senegal, Ph. D. thesis, University of Stirling, Stirling, Scotland.
3. Baldwin, P. J., Sabater Pi, J., McGrew, W. C., and Tutin, C. E. G. (1981). Comparison of nests made by different populations of chimpanzees(Pan troglodytes).Primates 22: 474–486.
4. Boaz, N. T. (1979). Early hominid population densities: New estimates.Science 206: 592–595.
5. Butzer, K. W. (1977). Environment, culture and human evolution.Am. Sci. 65: 572–584.