Sihem Amer-Yahia Zohra Bellahsene Ela Hunt Rainer Unland Jeffrey Xu Yu Database and XML Technologies, 4th International XML Database Symposium,XSym 2006, Seoul, Korea, September 10-11, 2006, Proceedings 4156 2006 3-540-38877-X XSym Lecture Notes in Computer Science Springer db/conf/xsym/xsym2006.html