Partoyo, P., Nursanto, E., Ilcham, A. and Supriyanta, B. 2025. Coal-Based Humic Acid Fertilizer Effects on Soil Properties and Mustard Growth. RSF Conference Series: Engineering and Technology. 4, 1 (Oct. 2025), 135–143. DOI:https://doi.org/10.31098/cset.v4i1.1000.