PURBA, Irvan Selamat; MARBU, Posma; FAUZI. Evaluasi Kesesuaian Lahan Untuk Tanaman Kopi Arabika (Coffea Arabica) di Kecamatan Pollung Kabupaten Humbang Hasundutan. Jurnal Online Pertanian Tropik, [S. l.], v. 5, n. 1, p. 61–60, 2018. DOI: 10.32734/jopt.v5i1.3135. Disponível em: https://idjpcr.usu.ac.id/jpt/article/view/3135. Acesso em: 19 dec. 2025.