A. Harrer, R. Hever, and S. Ziebarth. Artificial Intelligence in Education - Building Technology Rich Learning Contexts that Work, 158, page 503-510. Amsterdam, IOS Press, (2007)
J. Moskaliuk, J. Kimmerle, and U. Cress. Proceedings of the International Conference of the Learning Sciences 2008(Bd. 2, S. 99-106). Utrecht, The Netherlands: International Society of the Learning Sciences, page 99-106. (2008)