Li, Jianhui, Zhouyu Wang, Zhenju Jiang, and Shengqian Jiang. “Trifluoromethanesulfonic Acid As an Efficient Catalyst in the Reduction of Ketimines”. Asian Journal of Chemistry 23, no. 7 (March 24, 2011): 3101–3103. Accessed January 8, 2025. https://asianpubs.org/index.php/ajchem/article/view/10545.