Marcos Antonio Vaz Salles Jens-Peter Dittrich Shant Kirakos Karakashian Olivier René Girard Lukas Blunschi iTrails: Pay-as-you-go Information Integration in Dataspaces. 663-674 2007 conf/vldb/2007 VLDB http://www.vldb.org/conf/2007/papers/research/p663-vazsalles.pdf db/conf/vldb/vldb2007.html#SallesDKGB07