Stefano A. Cerri, William J. Clancey, Giorgos Papadourakis, Kitty Panourgia: Intelligent Tutoring Systems - 11th International Conference, ITS 2012, Chania, Crete, Greece, June 14-18, 2012. Proceedings. Lecture Notes in Computer Science 7315, Springer 2012, ISBN 978-3-642-30949-6