Cita APA

Pettingill, O. S. (1965). The bird watcher's America. New York: McCraw-Hill.

Citación estilo Chicago

Pettingill, Olin Sewall. The Bird Watcher's America. New York: McCraw-Hill, 1965.

Cita MLA

Pettingill, Olin Sewall. The Bird Watcher's America. New York: McCraw-Hill, 1965.