Mirza, Behrooz, and Sepehr Sadegh Samiei. “Synthesis of New Asymmetrical Dihydropyrimidinones in Presence of Oxalic Acid”. Asian Journal of Chemistry 24, no. 3 (December 13, 2011): 1293–1296. Accessed July 2, 2024. https://asianpubs.org/index.php/ajchem/article/view/8764.