@Inproceedings{EPTCS343.6,
  author    = {Zjawin, Beata and Wolfe, Elie  and Spekkens, Robert W. },
  year      = {2021},
  title     = {Restricted Hidden Cardinality Constraints in Causal Models},
  editor    = {Heunen, Chris and Backens, Miriam},
  booktitle = {{\rm Proceedings 18th International Conference on}
               Quantum Physics and Logic,
               {\rm Gdansk, Poland, and online, 7-11 June 2021}},
  series    = {Electronic Proceedings in Theoretical Computer Science},
  volume    = {343},
  publisher = {Open Publishing Association},
  pages     = {119-131},
  doi       = {10.4204/EPTCS.343.6},
}