https://www.rand.org/pubs/research_reports/RR2200.html
http://www.rug.nl/research/portal/files/41711829/cesifo1_wp6448.pdf
https://www.tuc.org.uk/news/cbi-and-tuc-call-prime-minister-change-brexit-approach?language=cy
http://europa.eu/rapid/press-release_MEMO-17-2001_en.htm