https://economicgraph.linkedin.com/resources/linkedin-workforce-report-uk-april-2018
https://eur-lex.europa.eu/eli/dir/2019/1152/oj
http://www.rug.nl/research/portal/files/41711829/cesifo1_wp6448.pdf
https://www.instituteforgovernment.org.uk/sites/default/files/publications/IfG_Brexit_customs_WEB.pdf