APA (7th ed.) Citation

Petersen, J. F., Sack, D. I., & Gabler, R. E. (2017). Physical geography (Eleventh edition.). Cengage Learning.

Chicago Style (17th ed.) Citation

Petersen, James F., Dorothy Irene Sack, and Robert E. Gabler. Physical Geography. Eleventh edition. Australia: Cengage Learning, 2017.

MLA (9th ed.) Citation

Petersen, James F., et al. Physical Geography. Eleventh edition. Cengage Learning, 2017.