D. Gruhl, R. Guha, D. Liben-Nowell, and A. Tomkins. WWW '04: Proceedings of the 13th international conference on World Wide Web, page 491--501. New York, NY, USA, ACM Press, (2004)
J. Freyne, R. Farzan, P. Brusilovsky, B. Smyth, and M. Coyle. IUI '07: Proceedings of the 12th international conference on Intelligent user interfaces, page 52--61. New York, NY, USA, ACM Press, (2007)
A. Hotho, R. Jäschke, C. Schmitz, and G. Stumme. The Semantic Web: Research and Applications, 3rd European Semantic Web Conference, ESWC 2006, Budva, Montenegro, volume 4011 of Lecture Notes in Computer Science, page 411-426. Berlin / Heidelberg, Springer, (11-14 June 2006)
U. Lee, Z. Liu, and J. Cho. WWW '05: Proceedings of the 14th International World Wide Web Conference, page 391--400. New York, NY, USA, ACM Press, (2005)
R. Kraft, and J. Zien. WWW '04: Proceedings of the 13th international conference on World Wide Web, page 666--674. New York, NY, USA, ACM Press, (2004)