Zhang, Peng-Fei, and Hong-Wen Gao. “Synthesis of P-Nitrobenzenediazoamido Black 10B and Its Application to Spectrophotometric Determination OfMicro Amount of Cadmium ”. Asian Journal of Chemistry, vol. 11, no. 2, Mar. 2010, pp. 484-9, https://asianpubs.org/index.php/ajchem/article/view/23308.