Gaya APA

purba, H, H., Aisyah, S. (2017). quality improvement and lean six sigma . Ruko jambu sari 7A yogyakrta : expert.

Gaya MLA

purba, Humiras, Hardi., Aisyah, Siti. "quality improvement and lean six sigma". Ruko jambu sari 7A yogyakrta : expert, 2017. Text Book Mesin.