APA

Ridgely R. S., Gwynne J. A., . (1989). A guide to the birds of Panama. New Jersey: Princeton University.

Chicago

Ridgely Robert S, Gwynne John A, . 1989. A guide to the birds of Panama. New Jersey: Princeton University.

Harvard

Ridgely R. S., Gwynne J. A., . (1989). A guide to the birds of Panama. New Jersey: Princeton University.

MLA

Ridgely Robert S, Gwynne John A, . A guide to the birds of Panama. New Jersey: Princeton University. 1989.