Dabas, P., and M.K. Rastogi. “Reactions of Di(Alkoxy) Dichlorooxotungsten(VI) With 2,2’-Bipyridyl ”. Asian Journal of Chemistry, vol. 9, no. 4, Mar. 2010, pp. 869-70, https://asianpubs.org/index.php/ajchem/article/view/23983.