Cita APA (7a ed.)

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

Cita Chicago Style (17a ed.)

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

Cita MLA (9a ed.)

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