Wei, Qingli, Cai-Feng Ding, Shu-Sheng Zhang, and Nian Liu. 2010. “Synthesis and Quantum Chemistry Study of Nitrogen-Containing Heterocyclic Ligands”. Asian Journal of Chemistry 18 (3):1895-1902. https://asianpubs.org/index.php/ajchem/article/view/20894.