
http://www.britishchambers.org.uk/press-office/press-releases/bcc-open-letter-to-pm-businesses-need-clarity-on-brexit.html

http://www.iata.org/whatwedo/Documents/economics/impact_of_brexit.pdf

http://blogs.lse.ac.uk/brexit/2018/05/15/switzerland-wanted-more-immigration-controls-but-economic-self-interest-will-probably-prevail/