Lepisto, Timo. Salomaa, Arto. Automata, languages and programming /ed. by Timo Lepisto and Arto Salomaa. - Berlin Springer-Verlag 1988 - xi, 741p includes bibl. - Lecture notes in computer science v.317 . ISBN: 3540194886 Dewey Class. No.: 001.6424 / N8846,N8846;1