| 1991 | Towards Kleene Algebra with Recursion. | Hans Lei |
| 1991 | Plausibility Logic. | Daniel Lehmann |
| 1991 | Logical Semantics of Modularisation. | Gerard R. Renardel de Lavalette |
| 1991 | Logical Inference and Polyhedral Projection. | John N. Hooker |
| 1991 | Safe Queries in Relational Databases with Functions. | Yoram Hirshfeld |
| 1991 | Some Aspects of the Probabilistic Behavior of Variants of Resolution. | Peter Heusch, Ewald Speckenmeyer |
| 1991 | On Transitive Closure Logic. | Erich Grdel |
| 1991 | Denotational Versus Declarative Semantics for Functional Programming. | Juan Carlos Gonzlez Moreno, Maria Teresa Hortal-Gonzlez, Mario Rodrguez-Artalejo |
| 1991 | The Cutting Plane Proof System with Bounded Degree of Falsity. | Andreas Goerdt |
| 1991 | On Bounded Theories. | Jrg Flum |
| 1991 | A Primitive Recursive Set Theory and AFA: On the Logical Complexity of the Largest Bisimulation. | Tim Fernando |
| 1991 | A New Approach to Abstract Data Types II: Computation on ADTs as Ordinary Computation. | Solomon Feferman |
| 1991 | How to Implement First Order Formulas in Local Memory Machine Models. | Elias Dahlhaus |
| 1991 | Provability in TBLL: A Decision Procedure. | Jawahar Chirimar, James Lipton |
| 1991 | Stable Logic. | Brigitte Bsli |
| 1991 | Model Checking of Persistent Petri Nets. | Eike Best, Javier Esparza |
| 1991 | Correctness Proof For the WAM with Types. | Christoph Beierle, Egon Brger |
| 1991 | The Expressive Power of Transitive Closue and 2-way Multihead Automata. | Yaniv Bargury, Johann A. Makowsky |
| 1990 | The Gap-Language-Technique Revisited. | Heribert Vollmer |
| 1990 | On the Tracking of Loops in Automated Deductions. | Manfred E. Szabo |
| 1990 | On the Existence of Fixpoints in Moore's Autoepistemic Logic and the Non-Monotonic Logic of McDermott and Doyle. | Robert F. Strk |
| 1990 | Expansions and Models of Autoepistemic Theories. | Cecylia Rauszer |
| 1990 | Nontrivial Lower Bounds for some NP-Problems on Directed Graphs. | Solomampionona Ranaivoson |
| 1990 | Ramsey's Theorem in Bounded Arithmetic. | Pavel Pudlk |
| 1990 | The Complexity of Adaptive Error-Correcting Codes. | Daniele Mundici |