https://blogs.lse.ac.uk/europpblog/2023/10/17/why-differentiation-is-now-at-the-heart-of-europes-political-system/
https://ec.europa.eu/commission/commissioners/2014-2019/andriukaitis/blog/likening-eu-ussr-not-unreasonable_en
https://www.ipg-journal.de/schwerpunkt-des-monats/illusionen/artikel/detail/illusion-die-eu-laesst-sich-demokratisieren-3144/