APA (7th ed.) Citation

Alden, P., Grossenheider, R. P., & Burt, W. H. (1987). Peterson first guide to mammals of North America. Houghton Mifflin.

Chicago Style (17th ed.) Citation

Alden, Peter, Richard Philip Grossenheider, and William Henry Burt. Peterson First Guide to Mammals of North America. Boston: Houghton Mifflin, 1987.

MLA (9th ed.) Citation

Alden, Peter, et al. Peterson First Guide to Mammals of North America. Houghton Mifflin, 1987.