Oklima, A.M., Sudarsono, ., Iskandar, . and Suryaningtyas, D.T. 2015. Utilizing Coal Ash and Humic Substances as Soil Ameliorant on Reclaimed Post-Mining Land. JOURNAL OF TROPICAL SOILS. 19, 3 (Oct. 2015), 161–169. DOI:https://doi.org/10.5400/jts.2014.v19i3.161-169.