E. Bogdanov, C. Ullrich, E. Isaksson, M. Palmér, and D. Gillet. Advances in Web-Based Learning - ICWL 2012 - 11th International Conference, Sinaia, Romania, September 2-4, 2012. Proceedings, volume 7558 of Lecture Notes in Computer Science, page 69-78. Springer, (2012)
K. Borau, C. Ullrich, J. Feng, and R. Shen. Advances in Web Based Learning - ICWL 2009, 8th International Conference, Aachen, Germany, August 19-21, 2009. Proceedings, volume 5686 of Lecture Notes in Computer Science, page 78-87. Springer, (2009)
P. Han, R. Shen, F. Yang, and Q. Yang. Australian Joint Conference on Artificial Intelligence, volume 2557 of Lecture Notes in Computer Science, page 704-713. Springer, (2002)