APA (7th ed.) Citation

National Geographic Television, Willumsen, G., & Kiley, R. (2009). 30 years of National Geographic specials. National Geographic.

Chicago Style (17th ed.) Citation

National Geographic Television, Gail Willumsen, and Richard Kiley. 30 Years of National Geographic Specials. [Washington, D.C.]: National Geographic, 2009.

MLA (8th ed.) Citation

National Geographic Television, et al. 30 Years of National Geographic Specials. National Geographic, 2009.

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