Ronald V. Book
Complexity Classes of Formal Languages
ICALP, 1972.
@inproceedings{ICALP-1972-Book, author = "Ronald V. Book", booktitle = "{Proceedings of the Colloquium on Automata, Languages and Programming}", isbn = "0-7204-2074-1", pages = "517--520", title = "{Complexity Classes of Formal Languages}", year = 1972, }