P. Backlund, и M. Hendrix. Games and Virtual Worlds for Serious Applications (VS-GAMES), 2013 5th International Conference on, стр. 1-8. (сентября 2013)
D. Spikol, и J. Eliasson. The 6th IEEE International Conference on Wireless, Mobile, and Ubiquitous Technologies in Education, стр. 137--141. IEEE, (2010)