APA (7th ed.) Citation

Kolby, J., & Vaughn, D. (2009). GMAT Math prep course. Nova Press.

Chicago Style (17th ed.) Citation

Kolby, Jeff, and Derrick Vaughn. GMAT Math Prep Course. Los Angeles, CA: Nova Press, 2009.

MLA (9th ed.) Citation

Kolby, Jeff, and Derrick Vaughn. GMAT Math Prep Course. Nova Press, 2009.

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