Hashemian, Saeedeh, et al. “Kinetic Catalytic Spectrophotometric Determination of Thiocyanate Ion Using the Oxidation of Thionine by Bromate”. Asian Journal of Chemistry, vol. 22, no. 4, Mar. 2010, pp. 3147-52, https://asianpubs.org/index.php/ajchem/article/view/11525.