APA (7th ed.) Citation

Richthofen, F. v. (1868). The natural system of volcanic rocks.

Chicago Style (17th ed.) Citation

Richthofen, Ferdinand von. The Natural System of Volcanic Rocks. San Francisco, 1868.

MLA (9th ed.) Citation

Richthofen, Ferdinand von. The Natural System of Volcanic Rocks. 1868.

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