Jaya, D., Widayati, T. W., Mustika, R. Y., & Suwardi, H. N. A. (2020). Enhancing coal tailing quality by Flotation Method using Biosurfactant from Lerak (Sapindusrarak De Candole). Eksergi, 17(1), 20–27. https://doi.org/10.31315/e.v17i1.3298