Oping, J. M. “DAYA SAING KOMODITI UNGULAN SEKTOR PERKEBUNAN DI SULAWESI UTARA”. Jurnal AGROBISNIS, vol. 1, no. 1, Apr. 2021, pp. 32-47, https://agrobisnis.faperta-ukit.ac.id/index.php/agrobisnis/article/view/20.