Cita APA (7th ed.)

Croneis, C., & Krumbein, W. C. (1936). Down to Earth: An introduction to geology. University of Chicago.

Cita Chicago (17th ed.)

Croneis, Carey, i William C. Krumbein. Down to Earth: An Introduction to Geology. Chicago: University of Chicago, 1936.

Cita MLA (9th ed.)

Croneis, Carey, i William C. Krumbein. Down to Earth: An Introduction to Geology. University of Chicago, 1936.