1. Evaluation of queries based on the extended relational calculi;Kobayashi;Int. J. Comput. Inform. Sci.,1981
2. On the semantic constraints and normal forms of database relations;Kobayashi;Int. J. Policy Inform.,1982
3. Fast methods for testing quantified relational calculus assertions;Bernstein,1982
4. Remarks on the algebra of non first normal form relations;Jaeschke,1982
5. A complete axiomatization for a large class of dependencies in relational databases;Sadri,1979