Optimal implementation of conjunctive queries in relational data bases, Proceedings of the 9th ACM Symposium on Theory of Computing, pp.77-90, 1977. ,
Conjunctive query containment revisited, Proceedings of the 5th International Conference on Database Theory, vol.1186, pp.56-70, 1997. ,
,
, Theoretical Computer Science, vol.141, pp.109-131, 1995.
Parameterized Complexity, 1999. ,
The parameterized complexity of relational database queries and an improved characterization of W [1, Combinatorics, Complexity, and Logic-Proceedings of DMTCS '96, pp.194-213, 1996. ,
Query evaluation via tree-decompositions, Proceedings of the 8th International Conference on Database Theory, vol.1973, pp.22-38, 2001. ,
The complexity of acyclic conjunctive queries, Proceedings of the 39th Annual Symposium on Foundations of Computer Science, pp.706-715, 1998. ,
Hypertree decompositions and tractable queries, Proceedings of the 18th ACM Symposium on Principles of Database Systems, pp.21-32, 1999. ,
Reducibilities among combinatorial problems, Complexity of Computer Computations, pp.85-103, 1972. ,
Conjunctive-query containment and constraint satisfaction, Proceedings of the 17th ACM Symposium on Principles of Database Systems, pp.205-213, 1998. ,
On the complexity of database queries, Proceedings of the 16th ACM Symposium on Principles of Database Systems, pp.12-19, 1997. ,
Graph minors V. Excluding a planar graph, Journal of Combinatorial Theory, Series B, vol.41, pp.92-114, 1986. ,
The Complexity of Decision Problems in Automata Theory, 1974. ,
The complexity of relational query languages, Proceedings of the 14th ACM Symposium on Theory of Computing, pp.137-146, 1982. ,
Algorithms for acyclic database schemes, 7th International Conference on Very Large Data Bases, pp.82-94, 1981. ,
Perspectives on database theory, Proceedings of the 36th Annual IEEE Symposium on Foundations of Computer Science, pp.224-246, 1995. ,