Dyfyniad APA
Hawkins, D. I., & Tull, D. S. (1993). Essentials of marketing research (6th ed.). Macmillan.
Dyfyniad Arddull Chicago
Hawkins, Del I., and Donald S. Tull. Essentials of Marketing Research. 6th ed. New York: Macmillan, 1993.
Dyfyniad MLA
Hawkins, Del I., and Donald S. Tull. Essentials of Marketing Research. 6th ed. Macmillan, 1993.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.