APA (7th ed.) Citation

Covey, S. (2006). The 6 most important decisions you'll ever make: A guide for teens. Simon and Schuster.

Chicago Style (17th ed.) Citation

Covey, Sean. The 6 Most Important Decisions You'll Ever Make: A Guide for Teens. New York: Simon and Schuster, 2006.

MLA (9th ed.) Citation

Covey, Sean. The 6 Most Important Decisions You'll Ever Make: A Guide for Teens. Simon and Schuster, 2006.