Naik, S., et al. “Studies on Some Anionic Complexes of Cobalt(II), Nickel(II) and Copper(II)&Mdash; Part(II) ”. Asian Journal of Chemistry, vol. 10, no. 2, Mar. 2010, pp. 238-40, https://asianpubs.org/index.php/ajchem/article/view/23591.