Yu, Hui, et al. “Sensitive Kinetic-Spectrophotometric Determination of Protein Based on Its Inhibitive Effect on the Decolorization of Dibromo-P-Methylsulfonazo”. Asian Journal of Chemistry, vol. 23, no. 9, June 2011, pp. 3984-8, https://asianpubs.org/index.php/ajchem/article/view/10777.