Ningsih, Indrawati Rahayu, and Ribangun Bamban Jakaria. “Analyzing Customer Satisfaction Using Importance Peformance Analysis (IPA) on 19 Liter Packaging Drinking Water Products”. Procedia of Engineering and Life Science 40 (July 28, 2023). Accessed May 19, 2024. https://pels.umsida.ac.id/index.php/PELS/article/view/1424.