Mulyanto, Imam Arie, and Jerry Heikal. “Customer Segmentation in B2B Professional Services Using RFM Analysis and Ethnographic Insights: Evidence from a 15-Year Longitudinal Study”. Journal Research of Social Science, Economics, and Management, vol. 5, no. 8, Mar. 2026, pp. 10854-65, doi:10.59141/jrssem.v5i8.1349.