Zailani, A., F. S. Harahap, H. Walida, and K. Rizal. “Identification of Soil Chemical Properties in Producing Oil Palm Plants in Kota Pinang District (Barumun Watershed Case Study)”. Proceeding of International Conference Technology, Economics, and Social Science, vol. 1, no. 1, Jan. 2026, pp. 712-6, https://journals.adaresearch.or.id/ictess/article/view/228.