https://www.ceps.eu/wp-content/uploads/2021/03/PI2021-05_The-power-surplus.pdf
http://www.guengl.eu/uploads/news-documents/Working_paper_Border_controls_on_cross_border_trade_in_goods.pdf
https://www.ipg-journal.de/regionen/europa/artikel/detail/aussenpolitik-nach-wildwest-manier-4419/
https://www.politico.eu/article/european-union-ukraine-war-debt-crisis-aid-loans-18-billion/?utm_source=POLITICO.EU&utm_campaign=7dcfda718f-EMAIL_CAMPAIGN_2023_01_23_03_37&utm_medium=email&utm_term=0_10959edeb5-7dcfda718f-%5BLIST_EMAIL_ID%5D