Heller,Robert, & Hindle,Tim. (2008). Selling successfully. Dorling Kindersley.
Dyfyniad Arddull ChicagoHeller,Robert, and Hindle,Tim. Selling Successfully. London: Dorling Kindersley, 2008.
Dyfyniad MLAHeller,Robert, and Hindle,Tim. Selling Successfully. Dorling Kindersley, 2008.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.