Yi, Fengping, Jie Gao, Lirong Zhang, and Xiaoyan Jiang. 2015. “New Bronsted-Lewis Acidic Quaternary Ammonium Ionic Liquids: Synthesis, Acidity Determination and Acidity-Catalytic Activity Relationship”. Asian Journal of Chemistry 27 (4):1260-64. https://doi.org/10.14233/ajchem.2015.17494.