C. van Nimwegen, H. van Oostendorp, D. Burgos, and R. Koper. ICLS '06: Proceedings of the 7th international conference on Learning sciences, page 785--791. International Society of the Learning Sciences, (2006)
C. van Nimwegen, H. van Oostendorp, D. Burgos, and R. Koper. ICLS '06: Proceedings of the 7th international conference on Learning sciences, page 785--791. International Society of the Learning Sciences, (2006)