“Pengendalian Kualitas Palm Kernel Oil (PKO) Menggunakan Metode Six Sigma Di PT. Letawa”. Jurnal Rekayasa Sistem Industri & Manajemen 2, no. 1 (March 30, 2024): 75–82. Accessed April 7, 2026. https://jurnal.fti.umi.ac.id/index.php/JRSI/article/view/557.