Purba, Elvis F, Nancy Nopeline, Lasma L Sianipar, and Lastri Lastri. “Mapping Development Disparities: A Typology of Regencies and Cities in North Sumatra Based on Economic, Human Development, and Income Distribution Indicators”. Jurnal Ekuilnomi 8, no. 1 (February 15, 2026): 247–258. Accessed February 23, 2026. https://jurnal.usi.ac.id/index.php/ekuilnomi/article/view/2101.