https://www.gov.uk/guidance/status-of-eu-nationals-in-the-uk-what-you-need-to-know
https://www.llri.lt/wp-content/uploads/2018/06/Labour-Migration_3.pdf
https://blogs.lse.ac.uk/brexit/2019/08/12/boris-johnsons-real-agenda-the-singapore-scenario/
http://www.bbc.com/news/uk-43782241