https://www.opendemocracy.net/uk/jeremy-gilbert/forty-years-of-failure-how-to-challenge-narrative-of-hard-brexit
http://blogs.lse.ac.uk/brexit/2018/05/15/switzerland-wanted-more-immigration-controls-but-economic-self-interest-will-probably-prevail/
https://ec.europa.eu/commission/publications/position-paper-essential-principles-citizens-rights_en