H. Hairani, R. Wahyudi, Gede Yogi Pratama, and M.Khaerul Ihsan, “Application of RFM Model and K-Means Algorithm in Customer Loyalty Segmentation of Indonesian Regional Water Utility Company (PDAM)”, IJECSA, vol. 5, no. 1, pp. 1–8, Mar. 2026, doi: 10.30812/ijecsa.v5i1.6087.