J. Golbeck, B. Parsia, and J. Hendler. Seventh International Workshop on Cooperative Information Agents (CIA-03), page 238-249. Helsinki, Finland, (August 2003)
B. Berendt, A. Hotho, and G. Stumme. International Semantic Web Conference, volume 2342 of Lecture Notes in Computer Science, page 264 - 278. Springer Verlag, (2002)