Pandey, R.N., et al. “Studies on Metal-Ligand Vibrations in the Complexes of Dioxomolybdenum(VI) and Zirconium(IV) With Dibenzyl Sulphide and Dibenzyl Selenide”. Asian Journal of Chemistry, vol. 5, no. 2, Mar. 2010, pp. 394-7, https://asianpubs.org/index.php/ajchem/article/view/24825.