Christian Bessiere George Katsirelos Nina Narodytska Claude-Guy Quimper Toby Walsh Decomposition of the NValue Constraint. 114-128 2010 CP http://dx.doi.org/10.1007/978-3-642-15396-9_12 conf/cp/2010 db/conf/cp/cp2010.html#BessiereKNQW10