https://bdi.eu/#/artikel/news/europa-muss-ein-worst-case-szenario-verhindern/
https://ukandeu.ac.uk/trade-migration-and-brexit/
http://www.icaew.com/-/media/corporate/files/technical/economy/brexit/eu-exit-charge.ashx
https://publications.parliament.uk/pa/cm201719/cmselect/cmniaf/329/329.pdf