Petersen, J. F., Sack, D. I., & Gabler, R. E. (2017). Physical geography (Eleventh edition.). Cengage Learning.
Chicago Style (17th ed.) CitationPetersen, James F., Dorothy Irene Sack, and Robert E. Gabler. Physical Geography. Eleventh edition. Australia: Cengage Learning, 2017.
MLA (9th ed.) CitationPetersen, James F., et al. Physical Geography. Eleventh edition. Cengage Learning, 2017.
Warning: These citations may not always be 100% accurate.