http://foodresearch.org.uk/wp-content/uploads/2016/03/Food-and-Brexit-briefing-paper-2.pdf
http://www.independent.co.uk/news/uk/politics/article-127-brexit-stop-what-is-it-single-market-eu-eea-theresa-may-article-50-a7955806.html
http://www.iata.org/whatwedo/Documents/economics/impact_of_brexit.pdf
https://publications.parliament.uk/pa/cm201719/cmselect/cmintrade/520/520.pdf