R. Krestel, G. Demartini, and E. Herder. Proc. of 2011 Joint International Conference on Digital Libraries (JCDL 2011), Ottawa, Ontario, Canada, June 13-17, 2011. ACM., (2011)
D. Skoutas, and M. Alrifai. In Proc. of 20th ACM international conference on Information and knowledge management (CIKM '11), ACM, New York, NY, USA, 221-230., (2011)
O. Alhabashneh, R. Iqbal, N. Shah, S. Amin, and A. James. Proceedings of the 19th International Conference on Conceptual Structures (ICCS 2011), volume 6828 of Lecture Notes in Computer Science, page 346-352. Springer, (2011)