Reference. Regular monoidal languages [earnshaw-sobocinski-2022-rml]

@InProceedings{earnshaw_et_al:LIPIcs.MFCS.2022.44,
  author =	{Earnshaw, Matthew and Soboci\'{n}ski, Pawe{\l}},
  title =	{{Regular Monoidal Languages}},
  booktitle =	{47th International Symposium on Mathematical Foundations of Computer Science (MFCS 2022)},
  pages =	{44:1--44:14},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-256-3},
  ISSN =	{1868-8969},
  year =	{2022},
  volume =	{241},
  editor =	{Szeider, Stefan and Ganian, Robert and Silva, Alexandra},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops-dev.dagstuhl.de/entities/document/10.4230/LIPIcs.MFCS.2022.44},
  URN =		{urn:nbn:de:0030-drops-168425},
  doi =		{10.4230/LIPIcs.MFCS.2022.44},
  annote =	{Keywords: monoidal categories, string diagrams, formal language theory, cartesian restriction categories}
}