Cita APA (7a ed.)

Levin, H. L. (1996). The earth through time (5th ed.). Saunders College Publishing.

Cita Chicago Style (17a ed.)

Levin, Harold L. The Earth Through Time. 5th ed. Forth Worth, U.S.A: Saunders College Publishing, 1996.

Cita MLA (9a ed.)

Levin, Harold L. The Earth Through Time. 5th ed. Saunders College Publishing, 1996.

Precaución: Estas citas no son 100% exactas.