Dyfyniad APA

Beckwith Harry. (1997). Selling the invisible: A field guide to modern marketing. Warner Books / Time Warner Company.

Dyfyniad Arddull Chicago

Beckwith Harry. Selling the Invisible: A Field Guide to Modern Marketing. NewYork ,USA: Warner Books / Time Warner Company, 1997.

Dyfyniad MLA

Beckwith Harry. Selling the Invisible: A Field Guide to Modern Marketing. Warner Books / Time Warner Company, 1997.

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