Automata, Languages and Programming 26th International Colloquium, ICALP'99, Prague, Czech Republic, July 11-15, 1999 Proceedings - Wiedermann, Jiri; Wiedermann, Jiri; Emde Boas, Peter van; Emde Boas, Peter van; Nielsen, Mogens; Nielsen, Mogens (Springer Berlin Heidelberg : Imprint: Springer, 1999)