M. Roussou, E. Kavalieratou, and M. Doulgeridis. IDC '07: Proceedings of the 6th international conference on Interaction design and children, page 77--80. New York, NY, USA, ACM, (2007)
M. Derntl, and R. Motschnig-Pitrik. Proceedings of the 14th International Conference of the Society for Information Technology & Teacher Education (SITE03), page 2379-2382. Albuquerque, New Mexico, USA, (2003)
Y. Kali, R. Levin-Peled, and Y. Dori. Computers in Human Behavior, 25 (5):
1067 - 1078(2009)Including the Special Issue: Design Patterns for Augmenting E-Learning Experiences.