title: the ccube constraint object-oriented database system sigmod conference. authors: alexander brodsky , pavel a. exarkhopoulo , victor e. segal , jia chen. venue: nan. year: 1999.0
title: object normal forms and dependency constraints for object-oriented schemata acm transactions on database systems ( tods ) 1997. authors: zahir tari , john stokes , stefano spaccapietra. venue: nan. year: nan