Ryan, W. T. (1971). Programmed learning aid for principles of marketing. Learning systems company.
استشهاد بنمط شيكاغوRyan, William T. Programmed Learning Aid for Principles of Marketing. Illinois: Learning systems company, 1971.
MLA استشهادRyan, William T. Programmed Learning Aid for Principles of Marketing. Learning systems company, 1971.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.