APA (7th ed.) Citation

Walcott, C. D. (1896). The Cambrian rocks of Pennsylvania. Department of the Interior, United States Geological Survey.

Chicago Style (17th ed.) Citation

Walcott, Charles D. The Cambrian Rocks of Pennsylvania. Washington, D.C.: Department of the Interior, United States Geological Survey, 1896.

MLA (9th ed.) Citation

Walcott, Charles D. The Cambrian Rocks of Pennsylvania. Department of the Interior, United States Geological Survey, 1896.