Kalia, K.C., Anil Kumar, and Rajeev Sharma. 2010. “Simultaneous Spectrophotometric Estimation of Cobalt(II) and Nickel(II) With Phenylazobenzaldoxime ”. Asian Journal of Chemistry 5 (3):559-62. https://asianpubs.org/index.php/ajchem/article/view/24871.