@techreport{zj08:tr-sub,
  title = "Which submodular functions are expressible using binary submodular functions?",
  author = "Stanislav \v{Z}ivn\'y and Peter G. Jeavons",
  year = "2008",
  address = "Oxford, UK",
  institution = "Computing Laboratory, University of Oxford",
  month = "June",
  number = "CS-RR-08-08",
  url = "http://www.cs.ox.ac.uk/files/628/RR-08-08.pdf",
}