W. Xu, K. Kreijns, and J. Hu. Technologies for E-Learning and Digital Entertainment, volume 3942 of Lecture Notes in Computer Science, Springer Berlin Heidelberg, (2006)
W. Xu, K. Kreijns, and J. Hu. Technologies for E-Learning and Digital Entertainment, volume 3942 of Lecture Notes in Computer Science, Springer Berlin Heidelberg, (2006)