Gaya APA

KHOLIL, A, S, ,, M. (2013). SIX SIGMA : QUALITY FOR BUSINESS IMPROVEMENT (1). YOGYAKARTA: GRAHA ILMU.

Gaya MLA

KHOLIL, AMIN, SYUKRON, ,, MUHAMMAD. "SIX SIGMA : QUALITY FOR BUSINESS IMPROVEMENT". 1 YOGYAKARTA: GRAHA ILMU, 2013. Text.