Harahap, Fitra Syawal, Hilwa Walida, Abdul Rauf, Iman Arman, Sudarijah Sudarijah, and Sulaiman Harahap. “Study of Soil Properties on Various Slopes in the Cultivation of 15-Year-Old People’s Rubber Plants in Janji Village, Bilah Hulu District, Labuhanbatu Regency”. Proceeding of International Conference Technology, Economics, and Social Science 1, no. 1 (January 25, 2026): 717-723. Accessed August 21, 2026. https://journals.adaresearch.or.id/ictess/article/view/229.