GUPTA PRAVEEN. (2004). SIX SIGMA BUSINESS SCORECARD. MCGRAW-HILL.
Chicago-čujuhus (17. p.)GUPTA PRAVEEN. SIX SIGMA BUSINESS SCORECARD. NEW YORK: MCGRAW-HILL, 2004.
MLA-čujuhus (9. p.)GUPTA PRAVEEN. SIX SIGMA BUSINESS SCORECARD. MCGRAW-HILL, 2004.
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