https://publications.parliament.uk/pa/cm201719/cmselect/cmcumeds/365/365.pdf
http://www.iata.org/whatwedo/Documents/economics/impact_of_brexit.pdf
https://publications.parliament.uk/pa/ld5801/ldselect/ldeucom/4/4.pdf
https://ukandeu.ac.uk/trade-migration-and-brexit/