https://www.sbs.strath.ac.uk/economics/fraser/20171129/GMB-Brexit-report.pdf
http://fedtrust.co.uk/our-work-on-europe/there-may-be-trouble-ahead-brexit-after-the-election/
http://www.europarl.europa.eu/cmsdata/115748/IPOL_IDA(2017)583130_EN.pdf
https://www.rand.org/pubs/research_reports/RR2200.html