B. Yang, and H. Garcia-Molina. Proc.\ 22nd International Conference on Distributed
Computing Systems, 2 - 5 July, 2002, Vienna,
Austria, IEEE Computer Society, (1998)
A. Löser, C. Tempich, B. Quilitz, S. Staab, W. Balke, and W. Nejdl. Proc.\ 4th International Semantic Web Conference,
ISWC 2005, volume 3729 of LNCS, page 491 -- 505. Galway, Ireland, Springer-Verlag GmbH, (November 2005)