https://www.bloomberg.com/news/articles/2017-08-25/brexit-bulletin-when-silence-isn-t-golden
https://www.fragomen.com/file/scottishfuturespdf
https://blogs.lse.ac.uk/brexit/2019/06/26/did-we-ever-really-understand-how-the-eu-works/
https://ec.europa.eu/commission/sites/beta-political/files/customs_controls_0.pdf