Ouri Wolfson Sam Chamberlain Konstantinos Kalpakis Yelena Yesha Modeling Moving Objects for Location Based Services. 46-58 2001 conf/nsf/2001 Infrastructure for Mobile and Wireless Systems http://link.springer.de/link/service/series/0558/bibs/2538/25380046.htm db/conf/nsf/imws2001.html#WolfsonCKY01