Lokhande, R.S., and Leena M. Khadke. “Spectrophotometric Determination of Nickel(II) Using 5-Bromo Salicylaldoxime As an Analytical Reagent”. Asian Journal of Chemistry, vol. 17, no. 4, June 2016, pp. 2343-6, https://asianpubs.org/index.php/ajchem/article/view/13987.