APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

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

MLA (9th ed.) Citation

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