@inproceedings{AlgebraicCharacterisation,
  author = "David Cohen and Martin Cooper and Peter Jeavons",
  booktitle = "Proceedings of CP'06",
  doi = "10.1007/11889205_10",
  number = "4204",
  pages = "107-121",
  series = "Lecture Notes in Computer Science",
  title = "An algebraic characterisation of complexity for valued constraints",
  url = "http://web.comlab.ox.ac.uk/oucl/research/areas/constraints/publications/CP06expressibility.pdf",
  year = "2006",
}