Luigi Palopoli Domenico Saccà Domenico Ursino Semi-Automatic Techniques for Deriving Interscheme Properties from Database Schemes. 239-273 1999 30 Data Knowl. Eng. 3 db/journals/dke/dke30.html#PalopoliSU99 http://dx.doi.org/10.1016/S0169-023X(99)00013-0