Nasution, A. F., and R. Adelina Harahap. “Analysis of Soil Biological Conditions in Organic and Inorganic Agriculture Areas in Tanah Datar Regency”. Jurnal Online Pertanian Tropik, vol. 8, no. 3, Feb. 2022, pp. 169-74, doi:10.32734/jopt.v8i3.7543.