S. Gaonkar, J. Li, R. Choudhury, L. Cox, and A. Schmidt. MobiSys '08: Proceeding of the 6th international conference on Mobile systems, applications, and services, page 174--186. New York, NY, USA, ACM, (2008)
K. Borau, C. Ullrich, J. Feng, and R. Shen. Advances in Web Based Learning - ICWL 2009, 8th International Conference, Aachen, Germany, August 19-21, 2009. Proceedings, volume 5686 of Lecture Notes in Computer Science, page 78-87. Springer, (2009)
C. Costa, G. Beham, W. Reinhardt, and M. Sillaots. Proceedings of the 2nd SIRTEL'08 Workshop on Social Information Retrieval for Technology Enhanced Learning, 382, Maastricht, The Netherlands, (September 2008)