https://blogs.lse.ac.uk/europpblog/2023/06/07/is-spain-set-to-follow-in-italys-footsteps/
https://www.d-kart.de/en/blog/2020/05/11/ultra-vires/
https://ec.europa.eu/commission/commissioners/2014-2019/andriukaitis/blog/likening-eu-ussr-not-unreasonable_en
http://www.economics-ejournal.org/economics/journalarticles/2017-4