APA (7th ed.) Citation

Gale Group, Perrin, W. F., Wursig, B. G., & Thewissen, J. G. M. (2002). Encyclopedia of marine mammals. Academic Press.

Chicago Style (17th ed.) Citation

Gale Group, William F. Perrin, Bernd G. Wursig, and J. G. M. Thewissen. Encyclopedia of Marine Mammals. San Diego, Calif: Academic Press, 2002.

MLA (9th ed.) Citation

Gale Group, et al. Encyclopedia of Marine Mammals. Academic Press, 2002.