APA (7th ed.) Citation

Gingrich, N., & Maple. (2008). A contract with the earth. Penguin Group (USA) Inc.

Chicago Style (17th ed.) Citation

Gingrich, Newt, and Maple. A Contract with the Earth. New York: Penguin Group (USA) Inc, 2008.

MLA (8th ed.) Citation

Gingrich, Newt, and Maple. A Contract with the Earth. Penguin Group (USA) Inc, 2008.

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