Diego Calvanese Giuseppe De Giacomo Maurizio Lenzerini Domenico Lembo Antonella Poggi Riccardo Rosati MASTRO-I: Efficient Integration of Relational Data through DL Ontologies. 2007 Description Logics http://ceur-ws.org/Vol-250/paper_76.pdf conf/dlog/2007 db/conf/dlog/dlog2007.html#CalvaneseGLLPR07