Bagheri, A., et al. “Determination of Cefotaxime in Pharmaceutical Preparations by Visible Spectrophotometry Using Methyl Orange and Indigo Carmine Dyes”. Asian Journal of Chemistry, vol. 24, no. 3, Dec. 2011, pp. 1252-4, https://asianpubs.org/index.php/ajchem/article/view/8751.