http://www.libdems.org.uk/brexit-challenge-justice#
https://institute.global/news/customs-and-exiting-european-union
https://www.nytimes.com/2017/05/29/opinion/britain-brexit-economy.html?_r=1
http://data.parliament.uk/writtenevidence/committeeevidence.svc/evidencedocument/treasury-committee/the-uks-economic-relationship-with-the-european-union/oral/72053.html