@article{ZJ09constraints,
  author = "Stanislav \v{Z}ivn\'y and Peter G. Jeavons",
  doi = "10.1007/s10601-009-9078-z",
  journal = "Constraints",
  title = "Classes of submodular constraints expressible by graph cuts",
  url = "http://zivny.cz/publications/zj09constraints-preprint.pdf",
  year = "2009",
}