Nkutha, C.S., et al. “Adsorption of Cr(VI), Pb(II) Ions and Methylene Blue Dye from Aqueous Solution Using Pristine and Modified Coral Limestone”. Asian Journal of Chemistry, vol. 32, no. 10, Sept. 2020, pp. 2624-32, doi:10.14233/ajchem.2020.22815.