Sahrim, and Kholilul Kholik. “Optimization of Performance at PDAM Tirtanadi, North Sumatra Province”. International Conference Epicentrum of Economic Global Framework (May 7, 2025): 134–144. Accessed January 30, 2026. https://proceeding.pancabudi.ac.id/index.php/ICEEGLOF/article/view/355.