https://publications.parliament.uk/pa/cm201719/cmselect/cmbeis/380/380.pdf
http://www.parliament.uk/documents/commons-committees/Exiting-the-European-Union/17-19/Cross-Whitehall-briefing/EU-Exit-Analysis-Cross-Whitehall-Briefing.pdf
https://www.gov.uk/government/news/pms-european-council-press-statement-20-october-2017
https://blogs.lse.ac.uk/brexit/2019/08/12/boris-johnsons-real-agenda-the-singapore-scenario/