Bogdan-Florin Marin Axel Hunger Stefan Werner Sorin Meila Christian Schuetz Roles of an Intelligent Tutor Agent in a Virtual Society. 237-244 2005 conf/saint/2005 SAINT http://doi.ieeecomputersociety.org/10.1109/SAINT.2005.55 db/conf/saint/saint2005.html#MarinHWMS05