LEE DONALD D. (1984). INDUSTRIAL MARKETING RESEARCH,TECHNIQUES & PRACTICES (2ND.). VAN NOSTRAND INC.
Lua i Stíl Chicago (17ú heag.)LEE DONALD D. INDUSTRIAL MARKETING RESEARCH,TECHNIQUES & PRACTICES. 2ND. NEW YORK: VAN NOSTRAND INC, 1984.
Lua MLA (9ú heag.)LEE DONALD D. INDUSTRIAL MARKETING RESEARCH,TECHNIQUES & PRACTICES. 2ND. VAN NOSTRAND INC, 1984.
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