@inproceedings{Zivny09:models,
  author = "Stanislav \v{Z}ivn\'y and Peter G. Jeavons",
  booktitle = "Proceedings of the 15th International Conference on Principles and Practice of Contraint Programming (CP'09)",
  doi = "10.1007/978-3-642-04244-7_64",
  number = "5732",
  series = "Lecture Notes in Computer Science",
  title = "The complexity of valued constraint models",
  url = "http://zivny.cz/publications/zj09cp-preprint.pdf",
  year = "2009",
}