Dandia, Anshu, et al. “Synthesis and Antifungal Activity of a Series of Trifluoromethyl Substituted Indole and Spiro Indole Derivatives ”. Asian Journal of Chemistry, vol. 9, no. 4, Mar. 2010, pp. 804-11, https://asianpubs.org/index.php/ajchem/article/view/23968.