APA (7th ed.) Citation

Steffen, A., & Gore, A. (2006). Worldchanging: A user's guide for the 21st century. Abrams.

Chicago Style (17th ed.) Citation

Steffen, Alex, and Al Gore. Worldchanging: A User's Guide for the 21st Century. New York: Abrams, 2006.

MLA (8th ed.) Citation

Steffen, Alex, and Al Gore. Worldchanging: A User's Guide for the 21st Century. Abrams, 2006.

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