C. Kemp, and K. Ramamohanarao. Proceedings of the 6th European Conference on Principles
of Data Mining and Knowledge Discovery (PKDD 2002), page 263--274. Berlin, Springer, (2002)
C. Herzog, M. Luger, and M. Herzog. Proceedings of the ESWC'07 workshop \"Bridging the Gap between Semantic Web and Web 2.0\", Innsbruck, Austria, (June 2007)
M. Coyle, and B. Smyth. IUI '07: Proceedings of the 12th international conference on Intelligent user interfaces, page 282--285. New York, NY, USA, ACM Press, (2007)
E. Agichtein, and Z. Zheng. KDD '06: Proceedings of the 12th ACM SIGKDD international conference on Knowledge discovery and data mining, page 902--908. New York, NY, USA, ACM Press, (2006)