Journal of Logic and Computation Bibliography Journal of Logic and Computation Bibliography Martin Grohe . Existential least fixed-point logic and its relatives. Selected references Ashok Chandra and David Harel. Structure and complexity of relational queries. Ashok K. Chandra and David Harel.
Horn clauses queries and generalizations.
A deductive system for existential least fixpoint logic. Stephen A. Cook. Path systems and language recognition. Hierarchies in transitive closure logic, stratified Datalog and infinitary logic. Complete problems for fixed-point logics.