Harris, Aulia, Sugiyono Madelan, and Ahmad Badawi Saluy. “QUALITY CONTROL OF ELEVATOR AND ESCALATOR MAINTENANCE SERVICES AT PT ABC SURABAYA”. Dinasti International Journal of Management Science 2, no. 6 (August 15, 2021): 874–888. Accessed July 1, 2025. https://dinastipub.org/DIJMS/article/view/860.