https://publications.parliament.uk/pa/ld201719/ldselect/ldeucom/129/129.pdf
https://uk.yahoo.com/news/wales-could-disappear-england-under-213835584.html
https://www.instituteforgovernment.org.uk/sites/default/files/publications/IfG_Brexit_customs_WEB.pdf
https://www.gov.uk/government/news/ip-and-brexit-the-facts