Volume 23, Number 1, 1990
: Communicating Processes, Scheduling, and the Complexity of Nondeterminism.
Volume 23, Number 2, 1990
: Single-Exception Sorting Networks and the Computational Complexity of Optimal Sorting Network Verification.
Volume 23, Number 3, 1990 Special Issue in Honor of Robert McNaughton, Part I
Volume 23, Number 4, 1990 Special Issue in Honor of Robert McNaughton, Part II
: It is Decidable Whether a Monadic Thue System is Canonical Over a Regular Set.