https://www.publications.parliament.uk/pa/ld201617/ldselect/ldeucom/116/116.pdf
http://www.cesifo-group.de/ifoHome/publications/working-papers/CESifoWP/CESifoWPdetails?wp_num=6448&CESifoWP.search=+
http://visual.ons.gov.uk/trading-places-uk-goods-trade-with-eu-partners/
http://www.cer.org.uk/sites/default/files/insight_JS_9.5.17.pdf