Rekomendasi Pemupukan NPK pada Tanaman Kakao (Theobroma Cacao) di Desa Metun Sajau Kecamatan Tanjung Palas Timur, Kabupaten Bulungan, Provinsi Kalimantan Utara: Recommendations For NPK Fertilization on Cocoa (Theobroma Cacao) Plants in Metun Sajau Village, East Tanjung Palas Sub-District, Bulungan District, North Kalimantan Province. Jurnal Ecosolum, v. 11, n. 2, p. 126–135, 30 Dec.2022.