Sadia, M., M. R. Jan, J. Shah, and A. ul-Haq. 2016. “Comparison of Simple and Chelated Amberlite IR-120 for Preconcentration and Determination of Cu(II) from Aqueous Samples”. Bulletin of the Chemical Society of Ethiopia 30 (1):39-54. https://doi.org/10.4314/bcse.v30i1.4.