1. Foundations of Databases;Abiteboul,1995
2. Expressiveness of linear vs. polynomial constraints in database query languages;Afrati,1994
3. Relational expressive power of constraint query languages;Benedikt,1995
4. On the structure of queries in constraint query languages;Benedikt,1996
5. The complexity of elementary algebra and geometry;Ben-Or;J. Comput. System Sci.,1986