M. Möller, S. Regel, and M. Sintek. The Semantic Web: Research and Applications, 6th European Semantic Web Conference, ESWC 2009, Heraklion, Crete, Greece, volume 5554 of Lecture Notes in Computer Science, Springer, Berlin, (2009)
J. Broekstra, A. Kampman, and F. van Harmelen. The Semantic Web -- ISWC 2002: First International Semantic Web Conference Sardinia, Italy, volume 2342 of Lecture Notes in Computer Science, Springer, Berlin, (2002)