Dyfyniad APA

(1929). The drift of civilization. New York: Simon and Schuster, inc.

Dyfyniad Arddull Chicago

The Drift of Civilization. New York: Simon and Schuster, inc, 1929.

Dyfyniad MLA

The Drift of Civilization. New York: Simon and Schuster, inc, 1929.

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