Azmi, Ulul, and Farida Pulansari. “Evaluation of Customer Satisfaction Level At PT. X Using Net Promoter Score Approach”. Heuristic 22, no. 1 (May 13, 2025): 21–30. Accessed January 12, 2026. https://jurnal.untag-sby.ac.id/index.php/HEURISTIC/article/view/12985.