http://cep.lse.ac.uk/pubs/download/brexit11.pdf
http://www.cer.eu/sites/default/files/bulletin_118_js-sl_article2.pdf
http://www.cer.org.uk/sites/default/files/insight_js_st_9.6.17.pdf
https://institute.global/sites/default/files/articles/Fixing-the-Northern-Ireland-Protocol-A-Way-Forward.pdf