Buttrus, N.H., et al. “Synthesis and Characterization of Ni2+, Cu2+ and Zn2+ Complexes With Benzimidazole-2-Thionate, Diphosphene and Their Reaction With Iodine”. Asian Journal of Chemistry, vol. 25, no. 9, Apr. 2013, pp. 4856-60, doi:10.14233/ajchem.2013.14125.