Cita APA

Ehlers, S. M., & Schaeffer, P. P. (1979). Owls of the west: Their ecology and conservation. California: National Audubon Society.

Citación estilo Chicago

Ehlers, Sharyn Marie,, y Philip P. Schaeffer. Owls of the West: Their Ecology and Conservation. California: National Audubon Society, 1979.

Cita MLA

Ehlers, Sharyn Marie,, y Philip P. Schaeffer. Owls of the West: Their Ecology and Conservation. California: National Audubon Society, 1979.