Asmarhansyah, . “Improving Soil Properties and Yield of Corn (Zea Mays L.) by Application of Organic Amendment on Abandoned Tin-Mining Land in Bangka Island”. JOURNAL OF TROPICAL SOILS, vol. 21, no. 3, Feb. 2017, pp. 141-5, doi:10.5400/jts.2016.v21i3.141-151.