Afriyani, Asia, Ali Martinus, and Inneke Fratiwi. 2025. “Utilization of Coal Burning Waste Fly Ash As a Soil Improving Material in Red Yellow Podsolic Soil”. Jurnal Lahan Suboptimal : Journal of Suboptimal Lands 14 (2):210-15. https://doi.org/10.36706/jlso.14.2.2025.727.