https://bdi.eu/media/pressecenter/#/artikel/news/brexit-wirft-seine-schatten-voraus/
https://www.publications.parliament.uk/pa/ld201617/ldselect/ldeucom/169/169.pdf
http://blogs.lse.ac.uk/brexit/2018/05/15/switzerland-wanted-more-immigration-controls-but-economic-self-interest-will-probably-prevail/
https://www.politico.eu/article/9-slippery-brexit-pledges/?utm_source=POLITICO.EU&utm_campaign=39a5c3d811-EMAIL_CAMPAIGN_2019_11_01_05_51&utm_medium=email&utm_term=0_10959edeb5-39a5c3d811-190380769