Ryan, W. T. (1971). Programmed learning aid for principles of marketing. Learning systems company.
Dyfyniad Arddull ChicagoRyan, William T. Programmed Learning Aid for Principles of Marketing. Illinois: Learning systems company, 1971.
Dyfyniad MLARyan, William T. Programmed Learning Aid for Principles of Marketing. Learning systems company, 1971.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.