APA (7th ed.) Citation

Dunn, J., & Alderfer, J. (2008). National Geographic field guide to the birds of eastern North America. National Geographic.

Chicago Style (17th ed.) Citation

Dunn, Jon, and Jonathan Alderfer. National Geographic Field Guide to the Birds of Eastern North America. Washington, D.C: National Geographic, 2008.

MLA (9th ed.) Citation

Dunn, Jon, and Jonathan Alderfer. National Geographic Field Guide to the Birds of Eastern North America. National Geographic, 2008.