"Chimpanzee." National Geographic. N.p., n.d. Web. 15 Apr. 2013. <http://animals.nationalgeographic.com/animals/mammals/chimpanzee/>.c
"Chimpanzee." - New World Encyclopedia. N.p., n.d. Web. 15 Apr. 2013. <http://www.newworldencyclopedia.org/entry/Chimpanzee>.
Martin, Patricia A. Fink. Chimpanzees. New York: Children's, 2000. Print.
Robinson, Claire. Chimpanzees. Crystal Lake, IL: Heinemann Library, 1997. Print.
"Chimpanzee." - New World Encyclopedia. N.p., n.d. Web. 15 Apr. 2013. <http://www.newworldencyclopedia.org/entry/Chimpanzee>.
Martin, Patricia A. Fink. Chimpanzees. New York: Children's, 2000. Print.
Robinson, Claire. Chimpanzees. Crystal Lake, IL: Heinemann Library, 1997. Print.