K. McNally, M. O'Mahony, B. Smyth, M. Coyle, and P. Briggs. Proceedings of the 16th international conference on Intelligent user interfaces, page 387--390. New York, NY, USA, ACM, (2011)
B. Karweg, C. Huetter, and K. Böhm. Proceedings of the 20th ACM international conference on Information and knowledge management, page 1825--1834. New York, NY, USA, ACM, (2011)
B. Hu, Y. Zhang, W. Chen, G. Wang, and Q. Yang. Proceedings of the 20th international conference on World wide web, page 17--26. New York, NY, USA, ACM, (2011)