Dyfyniad APA

Thornbury, W. D. (1954). Principles of geamorphology. (2nd ed.). Wiley Eastern.

Dyfyniad Arddull Chicago

Thornbury, William D. Principles of Geamorphology. 2nd ed. New Delhi: Wiley Eastern, 1954.

Dyfyniad MLA

Thornbury, William D. Principles of Geamorphology. 2nd ed. Wiley Eastern, 1954.

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