Dhingra, Vinod, et al. “Synthesis and Biological Activity of Some 1-Isonicotinoyl- 3,5-Diphenyl-4-4Substituted Phenyl Azo Pyrazoles ”. Asian Journal of Chemistry, vol. 5, no. 3, Mar. 2010, pp. 515-8, https://asianpubs.org/index.php/ajchem/article/view/24864.