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Lua i Stíl Chicago (17ú heag.)TULL DONALD S. MARKETING RESEARCH: MEASUREMENT AND METHOD. 6TH. NEW DELHI: PRENTICE -HALL INTERNATIONAL, INC, 2000.
Lua MLA (9ú heag.)TULL DONALD S. MARKETING RESEARCH: MEASUREMENT AND METHOD. 6TH. PRENTICE -HALL INTERNATIONAL, INC, 2000.
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