Nadia Creignou Phokion G. Kolaitis Heribert Vollmer Complexity of Constraints - An Overview of Current Research Themes [Result of a Dagstuhl Seminar]. 5250 2008 http://dx.doi.org/10.1007/978-3-540-92800-3 978-3-540-92799-0 Complexity of Constraints Lecture Notes in Computer Science Springer db/conf/dagstuhl/coc2008.html