Παραπομπή APA

Frye, R. W. (1973). Introduction to the marketing system. Comfield press, 1973.

Παραπομπή Chicago Style

Frye, Robert W. Introduction to the Marketing System. Francisco: Comfield press, 1973, 1973.

Παραπομπή MLA

Frye, Robert W. Introduction to the Marketing System. Comfield press, 1973, 1973.