V. Devedzic, J. Good, A. Harrer, R. Luckin, D. Pearce, S. Retalis, and J. Robertson. Artificial Intelligence in Education - Building Technology Rich Learning Contexts that Work, volume 158 of Frontiers in Artificial Intelligence and Applications, page 715. Amsterdam, IOS Press, (2007)
F. Decortis, A. Rizzo, and B. Saudelli. Interacting with Computers, 15 (6):
801 - 830(2003)From Computer Artefact to Instrument for Mediated Activity .Part 2 Learning Environments.
M. Scaife, Y. Rogers, F. Aldrich, and M. Davies. CHI '97: Proceedings of the SIGCHI conference on Human factors in computing systems, page 343-350. New York, NY, USA, ACM Press, (1997)