Cita APA

Ehlers, S. M., & Schaeffer, P. P. (1990). Proceedings of the National Audubon Society's Symposium on the birds of Mexico their ecology and conservation. California: National Audubon Society.

Citación estilo Chicago

Ehlers, Sharyn Marie,, y Philip P. Schaeffer. Proceedings of the National Audubon Society's Symposium On the Birds of Mexico Their Ecology and Conservation. California: National Audubon Society, 1990.

Cita MLA

Ehlers, Sharyn Marie,, y Philip P. Schaeffer. Proceedings of the National Audubon Society's Symposium On the Birds of Mexico Their Ecology and Conservation. California: National Audubon Society, 1990.