Chalil, Diana, and Riantri Barus. “Analysis of Smallholders’ Progress in Implementing Sustainable Management in North Sumatra, Indonesia”. Indonesian Journal of Agricultural Research 1, no. 3 (February 19, 2019): 246–259. Accessed November 4, 2025. https://dev-talenta.usu.ac.id/InJAR/article/view/677.