APA (7th ed.) Citation

National Geographic Society (U.S.) & Waring, R. (2009). Polar bears in trouble. Heinle/ Cengage Learning.

Chicago Style (17th ed.) Citation

National Geographic Society (U.S.) and Rob Waring. Polar Bears in Trouble. London: Heinle/ Cengage Learning, 2009.

MLA (9th ed.) Citation

National Geographic Society (U.S.) and Rob Waring. Polar Bears in Trouble. Heinle/ Cengage Learning, 2009.

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