APA (7e ed.) Bronvermelding

LEVIN, H. L. (1983). The earth through time.-- ed.2. Saunders College.

Chicago (17e ed.) Bronvermelding

LEVIN, Harold L. The Earth Through Time.-- Ed.2. New York: Saunders College, 1983.

MLA (9e ed.) Bronvermelding

LEVIN, Harold L. The Earth Through Time.-- Ed.2. Saunders College, 1983.