Sulakhudin, ., Syukur, A. and Sunarminto, B.H. 2013. Zeolite and Hucalcia as Coating Material for Improving Quality of NPK Fertilizer in Costal Sandy Soil. JOURNAL OF TROPICAL SOILS. 16, 2 (Jul. 2013), 99–106. DOI:https://doi.org/10.5400/jts.2011.v16i2.99-106.