APA (7th ed.) Citation

Verbeek, N. A. M., & Butler, R. W. (1999). Northwestern crow: Corvus caurinus. Birds of North America, Inc..

Chicago Style (17th ed.) Citation

Verbeek, Nicolaas A. M., and Robert William Butler. Northwestern Crow: Corvus Caurinus. Philadelphia: Birds of North America, Inc., 1999.

MLA (9th ed.) Citation

Verbeek, Nicolaas A. M., and Robert William Butler. Northwestern Crow: Corvus Caurinus. Birds of North America, Inc., 1999.