Hassan, K., and S. Mouhsen. “Spectrophotometric Determination for Mercury(II),Lead(II) and Zinc(II) With 2-[(6- Methyl-2-Benzothiazolylazo)]-4-Chloro Phenol As Organic Reagent”. Al-Qadisiyah Journal of Pure Science, Vol. 20, no. 4, Aug. 2018, pp. 38 -52, https://journalsc.qu.edu.iq/index.php/JOPS/article/view/862.