https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/502291/54284_EU_Series_No1_Web_Accessible.pdf
http://www.cer.org.uk/sites/default/files/insight_JS_9.5.17.pdf
http://fedtrust.co.uk/our-work-on-europe/there-may-be-trouble-ahead-brexit-after-the-election/