Sulma Hajijatur Ridlwana, Arifiani Agustin Amalia and Yeni Rahmawati (2025) “Internal Quality Control Analysis of Sgot and Sgpt Examination Using Levey-Jennings Graphics and Six Sigma at X Hospital Yogyakarta: Analisis Quality Control Internal Pemeriksaan Sgot dan Sgpt Menggunakan Grafik Levey-Jennings dan Six Sigma di RS X Yogyakarta”, Journal of Health (JoH), 12(1), pp. 060-068. doi: 10.30590/joh.v12n1.1002.