
https://www.euronews.com/2018/09/25/why-is-the-irish-border-issue-so-complex-euronews-answers

https://ukandeu.ac.uk/wp-content/uploads/2021/11/Brexit-and-Services-Trade-Working-Paper.pdf

https://blogs.lse.ac.uk/brexit/2021/02/04/indyref2-scottish-independence-would-be-2-3-times-more-costly-than-that-of-brexit-and-rejoining-the-eu-wouldnt-make-up-the-difference/