
https://www.publications.parliament.uk/pa/ld201617/ldselect/ldeucom/169/169.pdf

https://www.nytimes.com/2017/05/29/opinion/britain-brexit-economy.html?_r=1

http://www.guengl.eu/uploads/news-documents/Working_paper_Border_controls_on_cross_border_trade_in_goods.pdf