Dyfyniad APA

Kotler, P. (1991). Principles of marketing (5th ed.). Prentice-Hall.

Dyfyniad Arddull Chicago

Kotler, Philip. Principles of Marketing. 5th ed. New Delhi: Prentice-Hall, 1991.

Dyfyniad MLA

Kotler, Philip. Principles of Marketing. 5th ed. Prentice-Hall, 1991.

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