
https://www.sussex.ac.uk/webteam/gateway/file.php?name=briefing-paper-1.pdf&site=18

https://blogs.lse.ac.uk/europpblog/2023/06/19/is-differentiated-cooperation-the-way-forward-for-eu-foreign-policy/

https://www.institute.global/insights/geopolitics-and-security/windsor-framework-what-has-been-agreed-and-what-it-means-northern-ireland-protocol