Jinfeng Ni Chinya V. Ravishankar Bir Bhanu Probabilistic Spatial Database Operations. 140-158 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2750&spage=140 2003 conf/ssd/2003 SSTD db/conf/ssd/sstd2003.html#NiRB03