APA (7th ed.) Citation

National Geographic Society (U.S.), Dunn, J. L., & Alderfer, J. K. (2011). National Geographic field guide to the birds of North America (Sixth edition.). National Geographic Society.

Chicago Style (17th ed.) Citation

National Geographic Society (U.S.), Jon L. Dunn, and Jonathan K. Alderfer. National Geographic Field Guide to the Birds of North America. Sixth edition. Washington, D.C.: National Geographic Society, 2011.

MLA (8th ed.) Citation

National Geographic Society (U.S.), et al. National Geographic Field Guide to the Birds of North America. Sixth edition. National Geographic Society, 2011.

Warning: These citations may not always be 100% accurate.