Optari, Leni Kurnia, and Al Bina. “Sustainable Development in Sumatra Island: Spatial Distribution and Its Implications”. Priviet Social Sciences Journal 5, no. 5 (May 30, 2025): 93–101. Accessed September 2, 2025. http://www.journal.privietlab.org/index.php/PSSJ/article/view/618.