Snowdon 2004 — Snowdon C. T.
Sexual Selection and Communication // Sexual Selection in Primates: New and Comparative Perspectives. Cambridge, 2004.Steams 1972 — Stearns F. R.
Laughing: Physiology, Pathophysiology, Psychology, Pathopsychology, and Development. Springfield, 1972.de Waal 1989 — Waal F. B. M. de
(Frans B. M.) Peacemaking Among Primates. Cambridge (MA); L., 1989.de Waal 1998 — Waal F. B. M. de
(Frans B. M.) Chimpanzee Politics: Power and Sex Among Apes. Baltimore, 1998.Walters 1988 — Walters M. J.
The Dance of Life: Courtship in the Animal Kingdom. N.Y., 1988.Yerkes 1929 — Yerkes R. M., Yerkes A. W.
The Great Apes: A Study of Anthropoid Life. L., 1929.Yerkes, Learned 1925 — Yerkes R. M
., Learned B. W. Chimpanzee Intelligence and it’s Vocal Expressions. Baltimore, 1925.