Aburub , S. ., N. F. Ab Manaf, A. M. Rohisham, N. N. M. Zain, N. Nordin, and N. Y. Rahim. “Silica Modified With Choline chloride/Urea DES for Ligand-Free Cu(II) Adsorption”. Journal of the Serbian Chemical Society, Mar. 2026, doi:10.2298/JSC250829011A.