https://publications.parliament.uk/pa/cm201719/cmselect/cmfaff/514/514.pdf
https://www.instituteforgovernment.org.uk/sites/default/files/publications/IfG_Brexit_customs_WEB.pdf
https://capx.co/why-has-boris-become-the-standard-bearer-of-the-tory-right/
https://www.populismstudies.org/wp-content/uploads/2023/03/Download-Report-on-Bulgaria.pdf