M. Khalifa1, Nagy, et al. “Synthesis and Screening of Some Novel Substituted Indoles Contained Fused Triazolo[1,5-a]pyridine and Thiazolo[3,2-a]pyridine Derivatives”. Asian Journal of Chemistry, vol. 26, no. 23, Nov. 2014, pp. 8185-90, doi:10.14233/ajchem.2014.17869.