
https://carnegieendowment.org/files/2-24_Lehne-EU_Geopolitics.pdf

https://trybunal.gov.pl/en/hearings/judgments/art/11662-ocena-zgodnosci-z-konstytucja-rp-wybranych-przepisow-traktatu-o-unii-europejskiej

http://blogs.lse.ac.uk/brexit/2018/11/23/hubert-butler-essay-prize-what-happened-to-europe-without-frontiers/