APA (7th ed.) Citation

Keefer, W. R. The Geologic Story of Yellowstone National Park.

Chicago Style (17th ed.) Citation

Keefer, William R. The Geologic Story of Yellowstone National Park.

MLA (9th ed.) Citation

Keefer, William R. The Geologic Story of Yellowstone National Park.

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