APA (7th ed.) Citation

Kay, G. F., & Apfel, E. T. (1929). The pre-Illinoian pleistocene geology of Iowa.

Chicago Style (17th ed.) Citation

Kay, George F., and Earl T. Apfel. The Pre-Illinoian Pleistocene Geology of Iowa. [Des Moines], 1929.

MLA (9th ed.) Citation

Kay, George F., and Earl T. Apfel. The Pre-Illinoian Pleistocene Geology of Iowa. 1929.

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