Rivaie, A. A. “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, vol. 20, no. 1, Feb. 2016, pp. 29-36, doi:10.5400/jts.2015.v20i1.29-36.