Donappa, N., and S.B. Naikar. “Complexes of Zinc(II), Cadmium(II) and Mercury(II) Perchlorates With Substituted Benzimidazoles ”. Asian Journal of Chemistry, vol. 5, no. 3, Mar. 2010, pp. 617-24, https://asianpubs.org/index.php/ajchem/article/view/24882.