https://www.socialeurope.eu/brexit-status-quo-ex-ante
https://publications.parliament.uk/pa/cm201719/cmselect/cmintrade/520/520.pdf
https://www.esri.ie/system/files/publications/WP677_0.pdf
http://www.guengl.eu/uploads/news-documents/Working_paper_Border_controls_on_cross_border_trade_in_goods.pdf