Daniele Braga Diego Calvanese Alessandro Campi Stefano Ceri Florian Daniel Davide Martinenghi Paolo Merialdo Riccardo Torlone NGS: a framework for multi-domain query answering. 254-261 2008 ICDE Workshops http://dx.doi.org/10.1109/ICDEW.2008.4498328 conf/icde/2008w db/conf/icde/icdew2008.html#BragaCCCDMMT08