
https://www.swp-berlin.org/publikation/majority-voting-on-foreign-policy-decisions-a-transitional-approach-needs-parliamentary-oversight

https://blogs.lse.ac.uk/europpblog/2021/10/22/de-facto-differentiation-in-action-why-poland-will-stay-in-the-eu-with-or-without-the-blessing-of-brussels/

https://www.bruegel.org/sites/default/files/2024-08/Memos%202024.pdf