C. Wang, Y. Zhang, and F. Zhang. 2007 First IEEE International Symposium on Information Technologies and Applications in Education, page 238--243. IEEE, (November 2007)
Y. Shi, M. Larson, and A. Hanjalic. User Modeling, Adaption and Personalization, volume 6787 of Lecture Notes in Computer Science, chapter 26, Springer Berlin / Heidelberg, Berlin, Heidelberg, (2011)
B. Li, Q. Yang, and X. Xue. Proceedings of the 21st international jont conference on Artifical intelligence, page 2052--2057. San Francisco, CA, USA, Morgan Kaufmann Publishers Inc., (2009)