@Misc{unruh21registers,
  author = 	 {Dominique Unruh},
  title = 	 {Quantum and classical registers},
  howpublished = {\href{https://arxiv.org/abs/2105.10914}{arXiv:2105.10914} [cs.LO]},
  year = 	 2021}


@Misc{daws21unitalanswer,
  author = 	 {Matthew Daws},
  title = 	 {Answer to MathOverlow question ``Unital *-homomorphisms between matrices''},
  howpublished = {\url{https://mathoverflow.net/a/390180}},
  year = 	 2021,
  note = 	 {Last accessed 2021-10-12}}
