References

Maple, PHD, Terry L. Orangutan Behavior. New York: Van Nostrand Reinhold Company, 1980.

Fleagle, John G. Primate Adaptation & Evolution. San Diego: Academic Press, Inc., 1988.

Russon, Anne E. Orangutans Wizards of the Rainforest. New York: Firefly Books, 2004.

Shumaker, Robert W., and Beck. Benjamin B. Primates in Question. Washington: Smithsonian Books, 2003.

Sleeper, Barbara. Primates. San Francisco: Chronicle Books, 1997.

Nowak, Ronald M. Walker's Mammals of the World. 5th Edition. 1991.

Myers, P. 2000. “Cercopithecidae” (on-line), Animal Diversity Web.  Accessed July 30,2005 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Cercopithecidae.html

Heffner, Rickye S. Primate Hearing From a Mammalian Perspective. Toledo: Wiley-Liss, 2004.

"Great Apes Survival Project." UNEP. 21 Mar 2008 http://www.unep.org/grasp/Resources/index.asp

"Library and Information Service National Primate Research Center, University of Wisconsin-Madison." Primate Info Net. 21 Mar 2008 http://pin.primate.wisc.edu/factsheets/entry/orangutan