D. Kanejiya, A. Kumar, and S. Prasad. Proceedings of the HLT-NAACL 03 workshop on Building educational applications using natural language processing - Volume 2, page 53--60. Stroudsburg, PA, USA, Association for Computational Linguistics, (2003)
M. Mohler, and R. Mihalcea. Proceedings of the 12th Conference of the European Chapter of the Association for Computational Linguistics, page 567--575. Stroudsburg, PA, USA, Association for Computational Linguistics, (2009)
T. Kakkonen, N. Myller, J. Timonen, and E. Sutinen. EdAppsNLP 05: Proceedings of the second workshop on Building Educational Applications Using NLP, page 29--36. Morristown, NJ, USA, Association for Computational Linguistics, (2005)