Jain, C.P., et al. “Hydroxytriazenes As Metallochromic Indicators for Complexometric Determination of Ion in Complexometric Determination of Iron in Pharmaceutical Preparations ”. Asian Journal of Chemistry, vol. 12, no. 3, Mar. 2010, pp. 909-10, https://asianpubs.org/index.php/ajchem/article/view/23088.