Nurhawaisyah, Sitti Ratmi, et al. “Effect of Sulfuric Acid Concentration on the Leaching Behavior of Manganese Ore from Palludda Barru Regency”. Cognitia : International Engineering Journal, vol. 1, no. 3, Dec. 2025, pp. 122-8, https://doi.org/10.63288/ciej.v1i3.14.