Gaya APA

J.Duncan, D. et al (1979). Programmed Learning Aid For Retailing Modern Concepts And Practices (Ed.3). Georgetown: Richard D.Irwin Inc.

Gaya MLA

J.Duncan, Delbert. et al. "Programmed Learning Aid For Retailing Modern Concepts And Practices". Ed.3 Georgetown: Richard D.Irwin Inc, 1979. Text.