Dyfyniad APA

Collier, R. (1931). The Robert Collier Letter Book. New York ; London: McGraw-Hill Book Company.

Dyfyniad Arddull Chicago

Collier, Robert. The Robert Collier Letter Book. New York ; London: McGraw-Hill Book Company, 1931.

Dyfyniad MLA

Collier, Robert. The Robert Collier Letter Book. New York ; London: McGraw-Hill Book Company, 1931.

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