APA (7th ed.) Citation

Gaddum, L. W., & Knowles, H. L. (1953). Our physical environment: A problem approach. University of Florida.

Chicago Style (17th ed.) Citation

Gaddum, Leonard W., and Harold L. Knowles. Our Physical Environment: A Problem Approach. Boston, Mass.: University of Florida, 1953.

MLA (9th ed.) Citation

Gaddum, Leonard W., and Harold L. Knowles. Our Physical Environment: A Problem Approach. University of Florida, 1953.