Cita APA

Dunning, J. S., & Ridgely, R. S. (1987). South American Birds: A photographic aid to identification. Pennsylvania: Harrowood.

Citación estilo Chicago

Dunning, John S., y Robert S. Ridgely. South American Birds: A Photographic Aid to Identification. Pennsylvania: Harrowood, 1987.

Cita MLA

Dunning, John S., y Robert S. Ridgely. South American Birds: A Photographic Aid to Identification. Pennsylvania: Harrowood, 1987.