APA (7th ed.) Citation

Hart, J. F. (1972). Regions of the United States. Annals of the Association of American Geographers.

Chicago Style (17th ed.) Citation

Hart, John Fraser. "Regions of the United States." Annals of the Association of American Geographers 1972.

MLA (8th ed.) Citation

Hart, John Fraser. "Regions of the United States." Annals of the Association of American Geographers, 1972.

Warning: These citations may not always be 100% accurate.