https://www.publications.parliament.uk/pa/cm201617/cmselect/cmbeis/909/909.pdf
https://publications.parliament.uk/pa/cm201719/cmselect/cmfaff/514/514.pdf
https://www.gov.uk/government/news/david-davis-speech-at-ubs
https://www.euronews.com/2018/09/25/why-is-the-irish-border-issue-so-complex-euronews-answers