@phdthesis{z09:phdthesis,
  title = "The Complexity and Expressive Power of Valued Constraints",
  author = "Stanislav \v{Z}ivn\'y",
  year = "2009",
  school = "University of Oxford",
  url = "http://ora.ouls.ox.ac.uk/objects/uuid:63facf22-7c2b-4d4a-8b6f-f7c323759ca0",
}