U. Reimer, U. Heck, and S. Streit. Proceedings of the 7th International Conference on Practical Aspects of Knowledge Management, page 26--37. Berlin, Heidelberg, Springer-Verlag, (2008)
M. Mavrikis, and S. Gutierrez-Santos. Computers & Education, 54 (3):
641 - 651(2010)Learning in Digital Worlds: Selected Contributions from the CAL 09 Conference.
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)
H. Maldonado, B. Lee, S. Klemmer, and R. Pea. Minds, minds, and society. Proceedings of the Computer-supported Collaborative Learning Conference, page 486-495. New Brunswick, NJ, International Society of the Learning Sciences, (2007)