Berkowitz, E. N., Hartley,Steven W, & Rudelius,William. (1997). Marketing (5th ed.). Irwin.

Berkowitz, Eric N., Hartley,Steven W, and Rudelius,William. Marketing. 5th ed. Chicago, Ill.: Irwin, 1997.

Berkowitz, Eric N., et al. Marketing. 5th ed. Irwin, 1997.