Hidayat, S. et al. 2021. Study of Nickel Leaching Using Sulfuric Acid and Phosphoric Acid on The Selectivity Nickel Ore. Jurnal Pijar Mipa. 16, 3 (Jun. 2021), 393–396. DOI:https://doi.org/10.29303/jpm.v16i3.2602.