R. Raju, D. Dhivya, R. Saranya, and S. Abbinaya. International Journal of Innovative Science and Modern Engineering (IJISME), 1 (3):
72-75(February 2013)
K. Boyer, E. Ha, R. Phillips, M. Wallis, M. Vouk, and J. Lester. Proceedings of the Fourth Workshop on Innovative Use of NLP for Building Educational Applications, page 19--26. Stroudsburg, PA, USA, Association for Computational Linguistics, (2009)