
https://www.socialeurope.eu/2017/05/smooth-brexit-interests-germany-much-uk/

http://www.bertelsmann-stiftung.de/fileadmin/files/Projekte/Migration_fair_gestalten/IB_Study_MixedMigration2017_ENG.pdf

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