1. A semantics for complex objects and approximate queries;Buneman,1988
2. Generalization and a framework for query modification;Chaudhuri,1990
3. Using type inference and induced rules to provide intensional answers;Chu,1991
4. Scheduling periodic jobs that allow imprecise results;Chung;IEEE Trans. on Computers,1990
5. The historical relational data model (HRDM) revisited;Clifford,1993