https://blogs.lse.ac.uk/brexit/2019/10/23/long-read-the-makings-of-brexit-and-the-road-ahead/
http://www.cer.eu/sites/default/files/pb_ireland_brexit_6.7.17.pdf
http://www.consilium.europa.eu//media/32504/xt21004-ad01re02en18.pdf
http://www.wsta.co.uk/images/Brexit/Brexit_FINAL.pdf