Issa NB, Elmaghrabie A, Boras E. Determination of Cr (III) and Cr (VI) In Water by Selective Separation and Preconcentration on Hybrid Resin. etj [Internet]. 2022 Apr. 11 [cited 2024 Jul. 22];7(4):1213-9. Available from: http://everant.org/index.php/etj/article/view/598