| • |
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>. |
