APA (7th ed.) Citation

Gersmehl, P., Kammrath, W., & Gross, H. H. (1980). Physical geography. Saunders College.

Chicago Style (17th ed.) Citation

Gersmehl, Philip, William Kammrath, and Herbert Henry Gross. Physical Geography. Philadelphia: Saunders College, 1980.

MLA (9th ed.) Citation

Gersmehl, Philip, et al. Physical Geography. Saunders College, 1980.