VIJAYA RAJU, K., and T. BENARJI PATRUDU. “Analysis of Some Binary Transition Metal Ion Mixtures Using Iron(II) As a Reductant in Phosphoric Acid Medium”. Asian Journal of Chemistry, vol. 20, no. 3, Mar. 2010, pp. 2163-8, https://asianpubs.org/index.php/ajchem/article/view/19223.