Hadrien Cambazard Fabien Demazeau Narendra Jussien Philippe David Interactively Solving School Timetabling Problems Using Extensions of Constraint Programming. 190-207 2004 conf/patat/2004 PATAT http://dx.doi.org/10.1007/11593577_12 db/conf/patat/patat2004.html#CambazardDJD04