Singh, Pradeep Pratap, et al. “Synthesis of 3,4-Dihydropyrimidin-2(1H)-Ones Derivatives of Acid Sensitive Aldehydes Catalyzed by Lanthanum Nitrate in Ionic Liquids”. Journal of Materials NanoScience, vol. 3, no. 1, Feb. 2016, pp. 14-16, https://pubs.thesciencein.org/journal/index.php/jmns/article/view/208.