A. Balali Moghaddam, J. Svendsen, M. Tory, and A. Branzan Albu. Proceedings of the 2011 annual conference extended abstracts on Human factors in computing systems, page 2347--2352. New York, NY, USA, ACM, (2011)
U. Reimer, U. Heck, and S. Streit. Proceedings of the 7th International Conference on Practical Aspects of Knowledge Management, page 26--37. Berlin, Heidelberg, Springer-Verlag, (2008)