Laxminarayana, K., and K. Laxma Reddy. “Removal of Cr(VI) Ions from Aqueous Solution by Using Syzygium Cumini Seeds”. Asian Journal of Chemistry, vol. 24, no. 12, Aug. 2012, pp. 5771-4, https://asianpubs.org/index.php/ajchem/article/view/9988.