“Analisis Quality Control Internal Pemeriksaan Sgot Dan Sgpt Menggunakan Grafik Levey-Jennings dan Six Sigma Di RS X Yogyakarta: Internal Quality Control Analysis of Sgot and Sgpt Examination Using Levey-Jennings Graphics and Six Sigma at X Hospital Yogyakarta”. Journal of Health, vol. 12, no. 1, Aug. 2025, pp. 060-8, https://doi.org/10.30590/joh.v12n1.1002.