Dandale, S.G., et al. “Synthesis and Biological Evaluation of Novel of 6-(Substituted Phenyl)-2H-imidazo[1,2-a]imidazol-3-One”. Asian Journal of Chemistry, vol. 24, no. 12, Aug. 2012, pp. 5854-6, https://asianpubs.org/index.php/ajchem/article/view/10033.