APA (7th ed.) Citation

Kummel, B., & Gillespie, E. L. (1961). History of the earth: An introduction to historical geology. Freeman.

Chicago Style (17th ed.) Citation

Kummel, Bernhard, and Evan L. Gillespie. History of the Earth: An Introduction to Historical Geology. San Francisco, California: Freeman, 1961.

MLA (9th ed.) Citation

Kummel, Bernhard, and Evan L. Gillespie. History of the Earth: An Introduction to Historical Geology. Freeman, 1961.