Gregory Kucherov Michaël Rusinowitch Matching a Set of Strings with Variable Length don't Cares. 129-154 1997 178 Theor. Comput. Sci. 1-2 db/journals/tcs/tcs178.html#KucherovR97 http://dx.doi.org/10.1016/S0304-3975(97)88195-9