Utami, S. W., Tarigan, R. A. P., & Widianingsih, B. (2019). Characterization of Micronutrients and Heavy Metal Content in Organic Fertilizer Made From Fly Ash and Organic Waste. JOURNAL OF TROPICAL SOILS, 24(1), 11–16. https://doi.org/10.5400/jts.2019.v24i1.11-16