Sura Guna, and Yani Iriani. “Analisis Keterlambatan Penerbitan Setifikat Hasil Uji Menggunakan Metode Lean Six Sigma (Studi Kasus: PT X)”. Journal of Industrial Science and Mechanical Engineering, vol. 1, no. 1, Sept. 2025, pp. 83-94, https://journal.widyatama.ac.id/index.php/jisme/article/view/3041.