Παραπομπή APA

Thornbury, W. D. (1969). Principles of geomorphology (2nd ed.). John Wiley.

Παραπομπή Chicago Style

Thornbury, William. D. Principles of Geomorphology. 2nd ed. New York: John Wiley, 1969.

Παραπομπή MLA

Thornbury, William. D. Principles of Geomorphology. 2nd ed. John Wiley, 1969.