Van Asch, Theodore W. J., and I. Nyoman Sukmantalya Kesumajaya. “The Modelling of Soil Slip Erosion in the Upper Komering Area, South Sumatra - Province, Indonesia”. Geografia Fisica E Dinamica Quaternaria, vol. 16, no. 1, June 1993, pp. 81-86, https://www.gfdq.glaciologia.it/index.php/GFDQ/article/view/715.