Montazeri, Naser, et al. “Nano Fe3O4: A Novel and Magnetically Recyclable Catalyst for the Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles in Solvent-Free Conditions”. Asian Journal of Chemistry, vol. 25, no. 6, Jan. 2013, pp. 3463-6, doi:10.14233/ajchem.2013.13963.