APA (7th ed.) Citation

London, J., & Van Zyle, J. (2001). Gone again ptarmigan. National Geographic Society.

Chicago Style (17th ed.) Citation

London, Jonathan, and Jon Van Zyle. Gone Again Ptarmigan. Washington, D.C.: National Geographic Society, 2001.

MLA (8th ed.) Citation

London, Jonathan, and Jon Van Zyle. Gone Again Ptarmigan. National Geographic Society, 2001.

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