Cita APA (7th ed.)
Engel. James F. (1973). Consumer behavior (2nd ed.). Holt, Rinehart.
Cita Chicago (17th ed.)
Engel. James F. Consumer Behavior. 2nd ed. New York: Holt, Rinehart, 1973.
Cita MLA (9th ed.)
Engel. James F. Consumer Behavior. 2nd ed. Holt, Rinehart, 1973.
Atenció: Aquestes cites poden no estar 100% correctes.