APA (7th ed.) Citation

Zimen, E. (1981). The wolf, a species in danger. Delacorte Press.

Chicago Style (17th ed.) Citation

Zimen, Erik. The Wolf, a Species in Danger. New York, N.Y.: Delacorte Press, 1981.

MLA (9th ed.) Citation

Zimen, Erik. The Wolf, a Species in Danger. Delacorte Press, 1981.