Rafail Ostrovsky Charles Rackoff Adam Smith Efficient Consistency Proofs for Generalized Queries on a Committed Database. 1041-1053 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3142&spage=1041 2004 conf/icalp/2004 ICALP db/conf/icalp/icalp2004.html#OstrovskyRS04