M. Ruiz-Casado, E. Alfonseca, and P. Castells. Proceedings of the Atlantic Web Intelligence Conference, AWIC-2005, volume 3528 of Lecture Notes in Computer Science, Springer Verlag, (2005)
R. Landefeld, and H. Sack. in Proc. of SABRE Conference on Social Semantic Web (CSSW 2007),, volume P-113 of GI-Edition - Lecture Notes in Informatics (LNI), (2007)