Uludag, Nesimi, Oktay Asutay, and Medet Yakup. “Reactions of Methyl Acetylenecarboxylate With Heterocyclic Enamines: [2+2] Cycloadditions in Polar and Non-Polar Solvents”. Asian Journal of Chemistry 26, no. 4 (February 14, 2014): 971–974. Accessed July 22, 2024. https://asianpubs.org/index.php/ajchem/article/view/26_5_7.