https://ukandeu.ac.uk/explainers/the-european-political-community/
https://onlinelibrary.wiley.com/doi/epdf/10.1111/1467-923X.13172
https://ec.europa.eu/info/sites/info/files/strategic_foresight_report_2020_1.pdf
https://www.aspistrategist.org.au/is-the-europen-union-too-big-for-further-enlargement/