Beckwith Harry. (1997). Selling the invisible: A field guide to modern marketing. Warner Books / Time Warner Company.
Chicago (17e ed.) BronvermeldingBeckwith Harry. Selling the Invisible: A Field Guide to Modern Marketing. NewYork ,USA: Warner Books / Time Warner Company, 1997.
MLA (9e ed.) BronvermeldingBeckwith Harry. Selling the Invisible: A Field Guide to Modern Marketing. Warner Books / Time Warner Company, 1997.
Let op: Deze citaties zijn niet altijd 100% accuraat.