Pai, Nandini, Krishnakant Waghmode, and Dileep Khandekar. 2011. “Microwave Promoted Solvent-Free Biginelli Reaction for the One Pot Synthesis of Dihydropyrimidin-2-(1H)-Ones Catalyzed by Sulfamic Acid”. Asian Journal of Chemistry 23 (12):5217-19. https://asianpubs.org/index.php/ajchem/article/view/11131.