https://www.socialeurope.eu/brexit-can-be-stopped-but-the-window-of-opportunity-is-closing-fast
https://www.gov.uk/government/news/pms-european-council-press-statement-20-october-2017
http://ukandeu.ac.uk/an-utterly-pernicious-bill/
http://www.rug.nl/research/portal/files/41711829/cesifo1_wp6448.pdf