Rivaie, Achmad Arivin. “Changes in Soil Available Phosphorus, Leaf Phosphorus Content and Yield of Sword Bean (Canavalia Ensiformis (L.) DC.) by Application of SP-36 and Phosphate Rock on Acid Upland Soil of East Lampung”. JOURNAL OF TROPICAL SOILS 20, no. 1 (February 2, 2016): 29–36. Accessed August 25, 2025. https://journal.unila.ac.id/index.php/tropicalsoil/article/view/218.