@inproceedings{cz11:cp-triangles,
  title = "Tractable triangles",
  author = "Martin C. Cooper and Stanislav \v{Z}ivn\'y",
  year = "2011",
  booktitle = "{P}roceedings of the 17th {I}nternational {C}onference on {P}rinciples and {P}ractice of {C}onstraint {P}rogramming ({C}{P}'11)",
  pages = "195--209",
  publisher = "Springer",
  series = "Lecture Notes in Computer Science",
  url = "http://zivny.cz/publications/cz11cp-triangles-preprint",
  volume = "6876",
  doi = "10.1007/978-3-642-23786-7_17",
}