Siregar, Deasy Arryannur, and Komala Sari Nasution. “Peningkatan Produksi Tanaman Kopi Di Desa Sampean Kabupaten Tapanuli Selatan”. Jurnal Pengabdian Masyarakat Bangsa 2, no. 11 (January 8, 2025): 5005–5008. Accessed April 18, 2026. https://jurnalpengabdianmasyarakatbangsa.com/index.php/jpmba/article/view/1915.