Learning by Playing. Game-based Education System Design and Development 4th International Conference on E-Learning and Games, Edutainment 2009, Banff, Canada, August 9-11, 2009. Proceedings - Chang, Maiga; Kuo, Rita; Kinshuk; Chen, Gwo-Dong; Hirose, Michitaka (Springer Berlin Heidelberg : Imprint: Springer, 2009)