Wouter Gelade Marc Gyssens Wim Martens Regular Expressions with Counting: Weak versus Strong Determinism. 369-381 2009 MFCS http://dx.doi.org/10.1007/978-3-642-03816-7_32 conf/mfcs/2009 db/conf/mfcs/mfcs2009.html#GeladeGM09