1. Canonical regular expressions and minimal state graphs for definite events;Brzozowski,1962
2. Dot depth of star-free events;Cohen;J. Comput. System Sci.,1971
3. Algebraic theory of automata;Ginzburg,1968
4. About some properties of definite, reverse-definite and related automata;Ginzburg;IEEE Trans. on Electr. Comput.,1966
5. Representation of events in nerve nets and finite automata;Kleene,1954