@inproceedings{SoftConstraints,
  title = "Soft constraints: complexity and multimorphsims",
  author = "David Cohen and Martin Cooper and Peter Jeavons and Andrei Krokhin",
  year = "2003",
  booktitle = "Proceedings of CP'03",
  number = "2833",
  pages = "244--258",
  series = "Lecture Notes in Computer Science",
  url = "http://www.comlab.ox.ac.uk/activities/constraints/publications/CP03multimorphisms.pdf",
}