Darmawan, ., K. Kyuma, T. Masunaga, . Asmar, I. Darfis, and T. Wakatsuki. “The Long-Term Effect of Blanket Phosphorus Fertilizer Application on the Available P Content in Sawah Soils; Comparative Study in Java, Indonesia”. JOURNAL OF TROPICAL SOILS, vol. 14, no. 1, Jan. 2009, pp. 9-18, doi:10.5400/jts.2009.v14i1.9-18.