Sources list for CHIMPANZEES CHIMPS:

`Chimpanzees become Human?', available at www.whyevolution.com/chimps.html [accessed 11 May 2005]
Aliens and the Quest for Identity

Heltne, Paul G. Understanding Chimpanzees. Cambridge, MA: Harvard University Press, 1989.
Chimp Intelligence

Kohler, Wolfgang. The Mentality of Apes: A Report on the Intellectual and Social Processes of Nine Chimpanzees. New York: Pelican Press, 1957.
Chimp Intelligence

Braun, A. Ph.D & Gannon, Ph.D. (nd) "Did the PT evolve in a functional role in communication -related tasks in chimpanzees, as it did in humans?" available [Online] at: http://jinrui.zool.kyoto-u. ac.jp/ChimpHome/kenkyuE.html Braun, A. Ph.D & Gannon, Ph.D. (nd) "Did the PT evolve in a functional role in communication -related tasks in chimpanzees, as it did in humans?" available [Online] at: http://jinrui.zool.kyoto-u. ac.jp/ChimpHome/kenkyuE.html
Bonobos

Levinson, David A., Russell, Jamie L. Russell, and Hopkins, William D.: "Intentionality as measured in the persistence and elaboration of communication by chimpanzees (Pan troglodytes)" Child Development, Jan-Feb 2005, v. 16, iss. 1,
Non-Human Communication