https://rusi.org/sites/default/files/briefingpaper-france-uk-2017.pdf
https://ec.europa.eu/commission/presscorner/api/files/document/print/en/ip_22_1511/IP_22_1511_EN.pdf
https://centreonconstitutionalchange.ac.uk/sites/default/files/2021-04/Union%20at%20the%20Crossroads.pdf