R. Uli, M. Surachman, H. Nurfitri, H. Soeratin, and M. Miftah, “Strategic Transformation and Social Impact of Ultra Micro Finance: A Systematic Literature Review of PT Permodalan Nasional Madani (PNM) and Social Entrepreneurship”, BIEJ, vol. 8, no. 3, pp. 255-263, Aug. 2026.