Kotler, P. (1991). Principles of marketing (5th.). Prentic Hall.
Dyfyniad Arddull ChicagoKotler, Philip. Principles of Marketing. 5th. New Delhi: Prentic Hall, 1991.
Dyfyniad MLAKotler, Philip. Principles of Marketing. 5th. Prentic Hall, 1991.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.