Gaya APA
Purba, H, H., Aisyah, S.
(2017).
Quality Improvement and Lean Six Sigma
.
Yogyakarta:
Expert.
Gaya MLA
Purba, Humiras, Hardi., Aisyah, Siti.
"Quality Improvement and Lean Six Sigma".
Yogyakarta:
Expert,
2017.
Penelitian Dosen.