http://carnegieeurope.eu/2017/06/15/bringing-brexit-back-to-reality-pub-71262
https://www.nao.org.uk/wp-content/uploads/2018/10/The-UK-border-preparedness-for-EU-exit.pdf
http://blogs.lse.ac.uk/brexit/2017/09/28/the-eu-referendum-was-gerrymandered/
https://www.socialeurope.eu/brexit-status-quo-ex-ante