| 1991 | A Conditional Operator for CCS. | Juanito Camilleri |
| 1991 | Causal Models for Rational Algebraic Processes. | Amar Bouali, Robert de Simone |
| 1991 | Embedding as a Tool for Language Comparison: On the CSP Hierarchy. | Frank S. de Boer, Catuscia Palamidessi |
| 1991 | The Failure of Failures in a Paradigm for Asynchronous Communication. | Frank S. de Boer, Joost N. Kok, Catuscia Palamidessi, Jan J. M. M. Rutten |
| 1991 | Real Space Process Algebra. | Jos C. M. Baeten, Jan A. Bergstra |
| 1991 | Formal Techniques for Parallel Object-Oriented Languages. | Pierre America |
| 1991 | A Theory of Testing for ACP. | Luca Aceto, Anna Inglfsdttir |
| 1990 | Effective Solutions to Domain Equations - An Approach to Effective Denotational Semantics. | Serge Yoccoz |
| 1990 | Real-Time Behaviour of Asynchronous Agents. | Wang Yi |
| 1990 | On the Compositional Checking of Validity (Extended Abstract). | Glynn Winskel |
| 1990 | A Synchronous Calculus of Relative Frequency. | Chris M. N. Tofts |
| 1990 | Priority as Extremal Probability. | Scott A. Smolka, Bernhard Steffen |
| 1990 | Partial Order Logics for Elementary Net Systems: State- and Event-approaches. | Antonia Sinachopoulos |
| 1990 | Factorization of Finite State Machines under Observational Equivalence. | Huajun Qin, Philip Lewis |
| 1990 | Proving Termination of Communicating Programs. | Pawel Paczkowski |
| 1990 | Back and Forth Bisimulations. | Rocco De Nicola, Ugo Montanari, Frits W. Vaandrager |
| 1990 | A Temporal Calculus of Communicating Systems. | Faron Moller, Chris M. N. Tofts |
| 1990 | Rewriting as a Unified Model of Concurrency. | Jos Meseguer |
| 1990 | Ideal Specification Formalism + Expressivity + Compositionality + Decidability + Testability + ... | Kim Guldstrand Larsen |
| 1990 | Equivalences, Congruences, and Complete Axiomatizations for Probabilistic Processes. | Chi-Chang Jou, Scott A. Smolka |
| 1990 | Delay-Insensitive Circuits: An Algebraic Approach to their Design. | Mark B. Josephs, Jan Tijmen Udding |
| 1990 | Let's Make Models (Abstract). | C. A. R. Hoare |
| 1990 | Value-Passing in Process Algebras (Abstract). | Matthew Hennessy |
| 1990 | Transition System Specifications with Negative Premises (Extended Abstract). | Jan Friso Groote |
| 1990 | A New Strategy for Proving omega-Completeness applied to Process Algebra. | Jan Friso Groote |