S. Decker, and M. Frank. Proc.\ WWW Workshop on Application Design,
Development and Implementation Issues in the
Semantic Web, Net York City, NY, (May 2004)
P. Ziegler, C. Kiefer, C. Sturm, K. Dittrich, and A. Bernstein. 10th International Conference on Extending Database Technology (EDBT 2006), volume 3896 of Lecture Notes in Computer Science, page 59-76. Munich, Germany, March 26-31, Springer, (2006)