Deras, Stefanus. “Analisis Pendapatan Dan Kelayakan Usahatani Kopi Arabika Di Desa Paraduan, Kecamatan Ronggurnihuta, Kabupaten Samosir”. Jurnal Agriust 5, no. 2 (July 13, 2025). Accessed July 19, 2025. https://ejournal.ust.ac.id/index.php/AGRIUST/article/view/5143.