https://www.gov.uk/government/news/pms-european-council-press-statement-20-october-2017
http://www.parliament.uk/documents/commons-committees/Exiting-the-European-Union/17-19/Cross-Whitehall-briefing/EU-Exit-Analysis-Cross-Whitehall-Briefing.pdf
https://institute.global/news/tony-blair-parliaments-duty-brexit
https://www.ft.com/content/b638551a-68c3-11e7-8526-7b38dcaef614