https://publications.parliament.uk/pa/ld201719/ldselect/ldeucom/63/63.pdf
http://www.bakermckenzie.com/-/media/files/insight/publications/brexit_tradeflows.pdf?la=en
http://www.epc.eu/documents/uploads/pub_7865_realitybites.pdf
http://blogs.lse.ac.uk/politicsandpolicy/john-mills-ge2017/