https://www.socialeurope.eu/wp-content/uploads/2017/06/EURO-web.pdf
http://visual.ons.gov.uk/trading-places-uk-goods-trade-with-eu-partners/
http://www.bmwi.de/Redaktion/DE/Publikationen/Monatsbericht/schlaglichter-der-wirtschaftspolitik-05-2017.pdf?__blob=publicationFile&v=24
https://documents1.worldbank.org/curated/en/099152301082423951/pdf/IDU10e3b5c3c1eb9214f981ad6116416052537cd.pdf