Kolwalkar, S.D., and B.H. Mehta. “Structural Studied of Vanadyl(II), Cobalt(II) and Nickel(II) Complexes of Schiff Bases”. Asian Journal of Chemistry, vol. 8, no. 3, Mar. 2010, pp. 406-10, https://asianpubs.org/index.php/ajchem/article/view/24080.