Oscar H. Ibarra Bala Ravikumar Relating the Degree of Ambiguity of Finite Automata to the Succinctness of their Representation. 26-43 1987 conf/fsttcs/1987 FSTTCS db/conf/fsttcs/fsttcs87.html#IbarraR87 http://dx.doi.org/10.1007/3-540-18625-5_40