Citazione Stile APA (7a Edizione)

Gabler, R. E., Sager, R. J., Wise, D. L., & Petersen, J. F. (1999). Essentials of physical geography (Sixth edition.). Saunders College Publishers.

Citazione stile Chigago Style (17a edizione)

Gabler, Robert E., Robert J. Sager, Daniel L. Wise, e James F. Petersen. Essentials of Physical Geography. Sixth edition. Fort Worth: Saunders College Publishers, 1999.

Citatione MLA (9a ed.)

Gabler, Robert E., et al. Essentials of Physical Geography. Sixth edition. Saunders College Publishers, 1999.