Hatta, M., M. Syam, and D. P. Widiastuti. “Efficiency Test of IRRI Fertilizing Recommendations on Rainfed Low Land Rice Field in West Kalimantan”. JOURNAL OF TROPICAL SOILS, vol. 19, no. 1, Apr. 2015, pp. 25-33, doi:10.5400/jts.2014.v19i1.25-33.