HARAHAP, F. S.; WALIDA, H.; RAUF, A.; ARMAN, I.; SUDARIJAH, S.; HARAHAP, S. 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, v. 1, n. 1, p. 717-723, 25 Jan. 2026.