Παραπομπή APA

Kummel, B. (1961). History of the earth: :An introduction to historical geology. Eurasia.

Παραπομπή Chicago Style

Kummel, Bernhard. History of the Earth: :An Introduction to Historical Geology. New Delhi: Eurasia, 1961.

Παραπομπή MLA

Kummel, Bernhard. History of the Earth: :An Introduction to Historical Geology. Eurasia, 1961.