Thomas Brinkhoff Jürgen Weitkämper Continuous Queries within an Architecture for Querying XML-Represented Moving Objects. 136-154 2001 conf/ssd/2001 SSTD http://link.springer.de/link/service/series/0558/bibs/2121/21210136.htm db/conf/ssd/sstd2001.html#BrinkhoffW01