Kim Guldstrand Larsen Sven Skyum Glynn Winskel Automata, Languages and Programming, 25th International Colloquium, ICALP'98, Aalborg, Denmark, July 13-17, 1998, Proceedings ICALP Lecture Notes in Computer Science 1443 Springer 1998 3-540-64781-3 db/conf/icalp/icalp98.html