T. Zesch, I. Gurevych, and M. Mühlhäuser. Proceedings of Human Language Technologies: The Annual Conference of the North American Chapter of the Association for Computational Linguistics (NAACL-HLT), (2007)
F. Wu, and D. Weld. CIKM '07: Proceedings of the sixteenth ACM conference on Conference on information and knowledge management, page 41--50. New York, NY, USA, ACM, (2007)