S. Bateman, C. Brooks, and G. Mccalla. in Proc. Workshop on Applications of Semantic Web Technologies for e-Learning, at the 4th International Conference on Adaptive Hypermedia and Adaptive Web-based Systems, page 3--12. (2006)
S. Scott, and S. Matwin. Proceedings of ICML-99, 16th International Conference on Machine Learning, page 379--388. Bled, SL, Morgan Kaufmann Publishers, San Francisco, US, (1999)