R. Jäschke, L. Marinho, A. Hotho, L. Schmidt-Thieme, and G. Stumme. Knowledge Discovery in Databases: PKDD 2007, 11th European Conference on Principles and Practice of Knowledge Discovery in Databases, Warsaw, Poland, September 17-21, 2007, Proceedings, volume 4702 of Lecture Notes in Computer Science, page 506-514. Springer, (2007)
S. Niwa, T. Doi, and S. Honiden. ITNG '06: Proceedings of the Third International Conference on Information Technology: New Generations (ITNG'06), page 388--393. Washington, DC, USA, IEEE Computer Society, (2006)