Nurjaya, ., and Dedi Nursyamsi. 2013. “Effectiveness of Direct Application of Phosphate Rock in Upland Acid Inceptisols Soils on Available-P and Maize Yield”. JOURNAL OF TROPICAL SOILS 18 (1):1-9. https://doi.org/10.5400/jts.2013.v18i1.1-9.