Johnston, M. W. (2008). Relationship selling. Boston: McGraw-Hill/Irwin.
Dyfyniad Arddull ChicagoJohnston, Mark W. Relationship Selling. Boston: McGraw-Hill/Irwin, 2008.
Dyfyniad MLAJohnston, Mark W. Relationship Selling. Boston: McGraw-Hill/Irwin, 2008.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.