El-Shahat, M.F., and A.M.A. Shehata. “Adsorption of Lead, Cadmium and Zinc Ions from Industrial Wastewater by Using Raw Clay and Broken Clay-Brick Waste”. Asian Journal of Chemistry, vol. 25, no. 8, Mar. 2013, pp. 4284-8, doi:10.14233/ajchem.2013.13940.