Klaus-Dieter Schewe Bernhard Thalheim Semantics in Data and Knowledge Bases, Third International Workshop, SDKB 2008, Nantes, France, March 29, 2008, Revised Selected Papers 4925 2008 978-3-540-88593-1 SDKB Lecture Notes in Computer Science Springer db/conf/sdb/sdkb2008.html