https://publications.parliament.uk/pa/ld201719/ldselect/ldconst/69/69.pdf
http://www.rug.nl/research/portal/files/41711829/cesifo1_wp6448.pdf
http://www.ibec.ie/IBEC/Press/PressPublicationsdoclib3.nsf/vPages/Newsroom~uk%27s-brexit-approach-risks-damaging-uk-irish-relations-17-01-2017/%24file/Brexit+Priorities+Report.pdf
http://blogs.lse.ac.uk/brexit/2017/12/05/a-high-risk-game-of-chicken-is-being-played-over-the-irish-border/