“Pendugaan Tingkat Bahaya Erosi Pada Hutan Dan Lahan Kopi Arabika (Coffea Arabica) Di Kecamatan Sibolangit”. Jurnal Online Pertanian Tropik 5, no. 1 (April 1, 2018): 30–35. Accessed February 5, 2026. https://idjpcr.usu.ac.id/jpt/article/view/3131.