Siregar, Sri Mulyani, and Riki Rahmad. “Mapping of Landslide Prone Areas in Regencies South Tapanuli Based on Geographic Information System”. Jurnal Spatial Wahana Komunikasi dan Informasi Geografi 19, no. 2 (December 31, 2019): 8 - 19. Accessed July 9, 2025. http://103.8.12.212:33180/unj/index.php/spatial/article/view/11535.