APA (7th ed.) Citation

Heltne, P. G., & Marquardt, L. (1989). Understanding chimpanzees. Harvard University Press.

Chicago Style (17th ed.) Citation

Heltne, Paul G., and Linda Marquardt. Understanding Chimpanzees. Cambridge, Mass.: Harvard University Press, 1989.

MLA (9th ed.) Citation

Heltne, Paul G., and Linda Marquardt. Understanding Chimpanzees. Harvard University Press, 1989.