I. Guy, I. Ronen, and E. Wilcox. Proceedings of the 14th International Conference on Intelligent User Interfaces, page 77--86. New York, NY, USA, ACM, (2009)
D. Bernhard, and I. Gurevych. Proceedings of the Third Workshop on Innovative Use of NLP for Building Educational Applications, page 44--52. Stroudsburg, PA, USA, Association for Computational Linguistics, (2008)
M. Ekstrand, M. Ludwig, J. Konstan, and J. Riedl. Proceedings of the Fifth ACM Conference on Recommender Systems, page 133--140. New York, NY, USA, ACM, (2011)