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

https://www.nytimes.com/2017/05/29/opinion/britain-brexit-economy.html?_r=1

https://www.publications.parliament.uk/pa/cm201617/cmselect/cmintrade/817/817.pdf