
https://blogs.lse.ac.uk/brexit/2019/10/09/northern-ireland-depends-on-the-eus-fluid-borders-for-survival/

http://www.independent.co.uk/news/uk/politics/article-127-brexit-stop-what-is-it-single-market-eu-eea-theresa-may-article-50-a7955806.html

https://blogs.lse.ac.uk/brexit/2018/10/30/after-brexit-the-uk-should-be-able-to-re-enter-the-eu-if-it-wishes-to-do-so/