I. Singh, A. K. Sharma, D. Singh, and S. K. Yadav, “Synthesis and Analytical Applications of a New Heterocyclic Bis-azo Dye: 2,6-bis(7-Hydroxyacenaphthyl-8-Azo)Pyridine ”, ajc, vol. 15, no. 2, pp. 1069–1074, Mar. 2010.