THARANITHARAN, V., and K. SRINIVASAN. “Removal of Ni(II) from Aqueous Solution by Using Surfactant- EDTA Modified Amberlite XAD-7HP and Duolite XAD-761 Resins”. Asian Journal of Chemistry, vol. 21, no. 9, Mar. 2010, pp. 7163-72, https://asianpubs.org/index.php/ajchem/article/view/12219.