Dyfyniad APA

Petersen, J. F., Sack, D. I., & Gabler, R. E. (2015). Fundamentals of physical geography (Second edition.). Cengage.

Dyfyniad Arddull Chicago

Petersen, James F., Dorothy Irene Sack, and Robert E. Gabler. Fundamentals of Physical Geography. Second edition. Australia: Cengage, 2015.

Dyfyniad MLA

Petersen, James F., et al. Fundamentals of Physical Geography. Second edition. Cengage, 2015.

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