Kshirsagar, S.S., et al. “Microwave Assisted Synthesis and Pharmacological Screening of Novel 6-Methyl-2-Oxo- 4-Substituted 5-(5-Phenyl-1,3,4-Oxadiazole-2-Yl)-1,2,3, 4-Tetrahydropyrimidines”. Asian Journal of Chemistry, vol. 23, no. 4, Dec. 2010, pp. 1713-5, https://asianpubs.org/index.php/ajchem/article/view/10172.