Ofer Arieli Marc Denecker Bert Van Nuffelen Maurice Bruynooghe Database Repair by Signed Formulae. 14-30 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2942&spage=14 2004 conf/foiks/2004 FoIKS db/conf/foiks/foiks2004.html#ArieliDNB04