K. Möller, T. Heath, S. Handschuh, and J. Domingue. Proceedings of the 6th International Semantic Web Conference and 2nd Asian Semantic Web Conference (ISWC/ASWC2007), Busan, South Korea, volume 4825 of LNCS, page 795--808. Berlin, Heidelberg, Springer Verlag, (November 2007)