Database and XML technologies (vol. # 4156) : 4th International XML Database Symposium, XSym 2006, Seoul, Korea, September 10-11, 2006, Proceedings - Amer-Yahia, Sihem; Bellahsène, Zohra; Hunt, Ela; Unland, Rainer; Yu, Jeffrey Xu (Lecture Notes in Computer Science,, 2006)