Dolak, I. et al. 2010. Removal and Preconcentration of Pb(II), Cr(III), Cr(VI) from the Aqueous Solution and Speciation of Cr(III)-Cr(VI) by Using Functionalized Amberlite XAD-16 Resin with Dithioethylenediamine. Asian Journal of Chemistry. 22, 8 (Jun. 2010), 6117–6124.