Kristianingrum, S., Siswani, E. D., & Sulistyani, S. (2018). MODIFICATION OF VOLCANIC ASH OF KELUD AS SELECTIVE ADSORBENT MATERIAL FOR Zn(II) AND Cr(VI) METAL IONS. Jurnal Sains Dasar, 7(1), 35–43. https://doi.org/10.21831/jsd.v7i1.22246