http://visual.ons.gov.uk/trading-places-uk-goods-trade-with-eu-partners/
http://www.standard.co.uk/news/politics/boris-johnson-backed-by-ukip-in-general-election-a3530371.html
https://www.cfr.org/blog/power-and-financial-interdependence
https://www.eda.admin.ch/dam/dea/fr/documents/folien/Folien-Abkommen_fr.pdf