APA (7th ed.) Citation

Timmons, J. M., & Karlstrom, K. E. (2012). Grand Canyon geology: Two billion years of Earth's history. Geological Society of America.

Chicago Style (17th ed.) Citation

Timmons, J. Michael, and Karl E. Karlstrom. Grand Canyon Geology: Two Billion Years of Earth's History. Boulder, Colo.: Geological Society of America, 2012.

MLA (9th ed.) Citation

Timmons, J. Michael, and Karl E. Karlstrom. Grand Canyon Geology: Two Billion Years of Earth's History. Geological Society of America, 2012.