1. Acheson, R., An Introduction to the Chemistry of Heterocyclic Compounds, New York: Wiley, 1976, 3rd ed. p. 354.
2. Bansal Raj, K., Heterocyclic Chemistry, New Delhi: New Age International Publisher, 2010, 4th ed., p. 454.
3. Raman, N., Dhaveethuraja, J., and Sakthivel, A., J. Chem. Sci., 2007, vol. 119, p. 303. doi 10.1007/s12039-007-0041-5
4. Raman, N., Sakthivel, A., and Rajasekaran, K., Mycobiology, 2007, vol. 35, p. 150. doi 10.4489/MYCO.2007.35.3.150
5. Anupama, M., Padmaja, C., and Gyana, K., E-J. Chem., 2012, vol. 9, p. 389. doi org/10.1155/2012/291850