<hi xmlns="http://www.tei-c.org/ns/1.0" rend="bold">Lenzerini, Maurizio </hi>(2002): "Data integration: a theoretical perspective", in: <hi xmlns="http://www.tei-c.org/ns/1.0" rend="italic">PODS'02 - Proceedings of the twenty-first ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems </hi>: 233-246 <ref xmlns="http://www.tei-c.org/ns/1.0" target="http://dl.acm.org/citation.cfm?doid=543613.543644">http://dl.acm.org/citation.cfm?doid=543613.543644</ref> [letzter Zugriff 09. Oktober 2015].