Hatta, Muhammad. “A Site-Specific Fertilizer Recommendation Based on the Phosphorus and Potassium Status in Mempawah District, West Kalimantan”. JOURNAL OF TROPICAL SOILS 25, no. 2 (May 19, 2020): 93–106. Accessed July 31, 2025. https://journal.unila.ac.id/index.php/tropicalsoil/article/view/335.