Leopoldo E. Bertossi Jan Chomicki Alvaro Cortés-Calabuig Claudio Gutiérrez Consistent Answers from Integrated Data Sources. 71-85 2002 conf/fqas/2002 FQAS http://link.springer.de/link/service/series/0558/bibs/2522/25220071.htm db/conf/fqas/fqas2002.html#BertossiCCG02