SimbolonD. R.; SumawinataB.; DjajakiranaG. The Solubility of Nickel on Mixed Ultramafic Soil with Peat Soil at Saturated and Unsaturated Water Condition. Jurnal Ilmu Tanah dan Lingkungan, v. 25, n. 1, p. 25-29, 1 Apr. 2023.