@inproceedings{coeckeheunen:infdim,
  title = "Pictures of complete positivity in arbitrary dimension",
  author = "Bob Coecke and Chris Heunen",
  year = "2011",
  journal = "QPL 2011, Electronic Proceedings in Theoretical Computer Science",
  pages = "27-35",
  volume = "95",
  doi = "10.4204/EPTCS.95.4",
}