Lars Arge Andrew Chatham Efficient Object-Realtional Interval Management and Beyond. 66-82 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2750&spage=66 2003 conf/ssd/2003 SSTD db/conf/ssd/sstd2003.html#ArgeC03