
https://theconversation.com/us-and-european-economies-depend-heavily-on-immigrants-decades-of-data-reveal-just-how-much-261508

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

http://www.radiofree.org/us/why-diemuk-shouldnt-take-a-precise-position-on-the-brexit-negotiations-or-why-britain-is-screwed/