Citazione Stile APA (7a Edizione)

Ryan, W. T. (1971). Programmed learning aid for principles of marketing. Learning Systems Company.

Citazione stile Chigago Style (17a edizione)

Ryan, William T. Programmed Learning Aid for Principles of Marketing. Homewood, Illinois: Learning Systems Company, 1971.

Citatione MLA (9a ed.)

Ryan, William T. Programmed Learning Aid for Principles of Marketing. Learning Systems Company, 1971.