https://blogs.lse.ac.uk/europpblog/2021/10/22/de-facto-differentiation-in-action-why-poland-will-stay-in-the-eu-with-or-without-the-blessing-of-brussels/
https://www.gov.pl/web/primeminister/letter-from-prime-minister-mateusz-morawiecki-to-the-heads-of-governments-and-the-presidents-of-the-european-council-the-european-commission-and-the-european-parliament-on-relations-between-national-law-and-european-law
https://www.esri.ie/system/files/publications/SUSTAT106_1.pdf
https://www.lse.ac.uk/ideas/Assets/Documents/reports/LSE-IDEAS-The-Rise-of-Insurgent-Europeanism.pdf
https://www.newstatesman.com/world/europe/2021/09/the-fateful-chancellor-what-the-end-of-the-merkel-era-means-for-the-world
https://www.newstatesman.com/ideas/2021/02/what-does-it-mean-be-pro-european-today?mc_cid=4118481f79&mc_eid=286ad5ef5f
https://foreignpolicy.com/2021/07/09/angela-merkel-german-chancellor-europe-trade-euro-refugees-crisis/
https://blogs.lse.ac.uk/europpblog/2021/08/25/what-the-conference-on-the-future-of-europe-can-learn-from-the-failure-of-the-eu-constitution/
https://urldefense.com/v3/__http:/liseuse.harmattan.fr/978-2-343-22496-1__;!!DOxrgLBm!RvRbHRx6Kt_Im0YooeSKul-1pdH3rrehJbewxga1m1XfdG_l66dacHGtbssMnGHPjvgLKb6ClUlbH3wttsPZTQ$
https://www.swp-berlin.org/publications/products/arbeitspapiere/WP_03-2021_EPIN-Report_CoFoE_01.pdf