https://blogs.sussex.ac.uk/uktpo/2017/06/12/disentangling-brexit-trade-politics-and-policies/
https://centreonconstitutionalchange.ac.uk/sites/default/files/2021-04/Union%20at%20the%20Crossroads.pdf
http://www.iata.org/whatwedo/Documents/economics/impact_of_brexit.pdf
http://www.cer.eu/sites/default/files/bulletin_118_js-sl_article2.pdf