Dyfyniad APA

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

Dyfyniad Arddull Chicago

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

Dyfyniad MLA

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

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.