1. Lecture Notes in Computer Science;M. Broy,1986
2. Lecture Notes in Computer Science;M. Wirsing,1980
3. Broy, M., Wirsing, M.: Initial versus terminal algebra semantics for partially defined abstract types. Technische Universität München, Institut für Informatik, TUM-I8018 (December 1981), Revidierte Fassung: Partial Abstract Types, Acta Informatica 18, 47–64 (1982)
4. Broy, M., Pepper, M., Wirsing, M.: On the algebraic definition of programming languages. Technische Universität München, Institut für Informatik, TUM-I8204 (1982), Revised version in TOPLAS 9(1) 54–99 (1987)
5. de Bakker, J.W., Zucker, J.I.: Processes and the denotational semantics of concurrency. Information and Control 54(1/2), 70–120 (1984)