https://blogs.lse.ac.uk/brexit/2019/04/15/brexit-lessons-from-the-silesian-backstop-of-1919-25/
https://www.socialeurope.eu/2017/07/road-soft-brexit/
https://ukandeu.ac.uk/long-read/the-protocol-post-brexit-northern-ireland/?mc_cid=9de7c359e6&mc_eid=815b1928ec
https://www.brexitloket.nl/impactscan