Tull, D. S., Hawkins, D. I., & Stewart, C. E. (1993). Marketing research: Measurement and method: a text with cases (6th ed.). Macmillon publishing company.
Chicago-tyylinen lähdeviittausTull, Donald S., Del I. Hawkins, ja Charles E,ed Stewart. Marketing Research: Measurement and Method: A Text with Cases. 6th ed. New York: Macmillon publishing company, 1993.
MLA-viiteTull, Donald S., et al. Marketing Research: Measurement and Method: A Text with Cases. 6th ed. Macmillon publishing company, 1993.
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