CONCUR '91 : 2nd International Conference on Concurrency Theory, Amsterdam, the Netherlands, August 26-29, 1991 : proceedings - International Conference on Concurrency Theory; Baeten, J. C. M.; Groote, J. F. (Jan Frisco); Centrum voor Wiskunde en Informatica (Amsterdam, Netherlands); Universiteit van Amsterdam; European Research Consortium for Informatics and Mathematics (Lecture notes in computer science, 1991)