Gaya APA

Perrins, C, M. (1991). The Illustrated Encyclopedia of BIRDS : The Definitive Reference to Birs of the World . New York: Prentice-Hall.

Gaya MLA

Perrins, Christopher, M. "The Illustrated Encyclopedia of BIRDS : The Definitive Reference to Birs of the World". New York: Prentice-Hall, 1991. .