@Inproceedings{EPTCS172.22,
  author    = {Heunen, Chris and Vicary, Jamie and Wester, Linde},
  year      = {2014},
  title     = {Mixed quantum states in higher categories},
  editor    = {Coecke, Bob and Hasuo, Ichiro and Panangaden, Prakash},
  booktitle = {{\rm Proceedings of the 11th workshop on}
               Quantum Physics and Logic,
               {\rm Kyoto, Japan, 4-6th June 2014}},
  series    = {Electronic Proceedings in Theoretical Computer Science},
  volume    = {172},
  publisher = {Open Publishing Association},
  pages     = {304-315},
  doi       = {10.4204/EPTCS.172.22},
}