1. Academic Press, New York, 1970. (b) Gribble, G. W. Heterocyclic Scaffolds II: Reactions and Applications of Indoles, In Top. Heterocycl. Chem. Vol. 26
2. Choi, E. H. Molecules 2013, 18, 6620.
3. (a) Sundberg, R. J. The Chemistry of Indoles; Academic Press, New York, 1970.
4. (b) Gribble, G. W. Heterocyclic Scaffolds II: Reactions and Applications of Indoles, In Top. Heterocycl. Chem. Vol. 26; Springer-Verlag, Berlin, Heidelberg, 2010.
5. (c) Kaushik, N. K.; Kaushik, N.; Attri, P.; Kumar, N.; Kim, Ch. H.; Verma, A. K.; Choi, E. H. Molecules 2013, 18, 6620.