Liu, L. Y. H. and Shyamasundar, R. K. "An operational semantics of real time design language RT-CDL" Proceedings of the 5th International Workshop on Software Specifications & Design Pittsburgh, Pennsylvania, United States 1989 pp75-82

Languages mentioned

• Ada {1979} US DoD general purpose language
• Esterel {1984}
• RT-CDL {1989}
• Statecharts {1987}