conf/sigmod/88 Alexander Borgida Modeling Class Hierarchies with Contradictions. 434-443 1988 SIGMOD Conference db/conf/sigmod/sigmod88.html#Borgida88 http://doi.acm.org/10.1145/50202.50254 db/conf/sigmod/Borgida88.html SIGMOD88/P434.PDF conf/sigmod/NixonCLBMS87 ... ... journals/tods/Borgida85 ... conf/sigmod/BunemanA86 ... journals/csur/CardelliW85 conf/vldb/ChanDFLNR82 conf/vldb/ChanDFR83 journals/tods/SmithS77