LEHMANN DONALD R. (1985). MARKET RESEARCH AND ANALYSIS (2ND.). IRWIN.
Chicago Style aipamenaLEHMANN DONALD R. MARKET RESEARCH AND ANALYSIS. 2ND. HOMWOOD: IRWIN, 1985.
MLA aipamenaLEHMANN DONALD R. MARKET RESEARCH AND ANALYSIS. 2ND. IRWIN, 1985.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.