APA (7th ed.) Citation

Gabler, R. E., Petersen, J. F., & Sack, D. (2012). Physical Geography. Brooks/Cole Cengage Learning.

Chicago Style (17th ed.) Citation

Gabler, Robert E., James F. Petersen, and Dorothy Sack. Physical Geography. Brooks/Cole Cengage Learning, 2012.

MLA (8th ed.) Citation

Gabler, Robert E., et al. Physical Geography. Brooks/Cole Cengage Learning, 2012.