Salomaa, Arto Formal languages. (English) Zbl 0262.68025 ACM Monograph Series. New York-London: Academic Press. XIII,322 p. $ 19.00 (1973). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 11 ReviewsCited in 492 Documents MSC: 68Q45 Formal languages and automata 68-02 Research exposition (monographs, survey articles) pertaining to computer science 03D05 Automata and formal grammars in connection with logical questions PDF BibTeX XML OpenURL Online Encyclopedia of Integer Sequences: Numbers that contain only 1’s, 2’s and 3’s.