Johnston, M. W. (2008). Relationship SellingMark W. Johnston and Greg W. Mashall. McGraw-Hill.
Dyfyniad Arddull ChicagoJohnston, Mark W. Relationship SellingMark W. Johnston and Greg W. Mashall. McGraw-Hill, 2008.
Dyfyniad MLAJohnston, Mark W. Relationship SellingMark W. Johnston and Greg W. Mashall. McGraw-Hill, 2008.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.