Consistent query answering under primary keys: a characterization of tractable queries.

Jef Wijsen Consistent query answering under primary keys: a characterization of tractable queries. 42-52 2009 ICDT http://doi.acm.org/10.1145/1514894.1514900 conf/icdt/2009 db/conf/icdt/icdt2009.html#Wijsen09