Παραπομπή APA

Tull, D. S., & Hawkins, D. I. (1990). Marketing research (5th ed.). MacMillan.

Παραπομπή Chicago Style

Tull, Donald S., και Del I. Hawkins. Marketing Research. 5th ed. United states: MacMillan, 1990.

Παραπομπή MLA

Tull, Donald S., και Del I. Hawkins. Marketing Research. 5th ed. MacMillan, 1990.