APA (7th ed.) Citation

Perrin, W. F., Würsig, B. G., & Thewissen, J. G. M. (2009). Encyclopedia of marine mammals (2nd ed.). Academic Press.

Chicago Style (17th ed.) Citation

Perrin, William F., Bernd G. Würsig, and J. G. M. Thewissen. Encyclopedia of Marine Mammals. 2nd ed. Amsterdam ; Boston: Academic Press, 2009.

MLA (9th ed.) Citation

Perrin, William F., et al. Encyclopedia of Marine Mammals. 2nd ed. Academic Press, 2009.