BURNS A. C., BUSH R. F., . (1997). MARKETING RESEARCH. NEW YORK: PRENTICE HALL.
BURNS ALVIN C, BUSH RONALD F, . 1997. MARKETING RESEARCH. NEW YORK: PRENTICE HALL.
BURNS ALVIN C, BUSH RONALD F, . MARKETING RESEARCH. NEW YORK: PRENTICE HALL. 1997.