Carlos Ansótegui Maria Luisa Bonet Jordi Levy Felip Manyà The Logic Behind Weighted CSP. 32-37 2007 conf/ijcai/2007 IJCAI http://dli.iiit.ac.in/ijcai/IJCAI-2007/PDF/IJCAI07-003.pdf db/conf/ijcai/ijcai2007.html#AnsoteguiBLM07