
https://ec.europa.eu/commission/publications/position-paper-transmitted-eu27-goods-placed-market-under-union-law-withdrawal-date_en

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.europarl.europa.eu/at-your-service/files/be-heard/eurobarometer/2019/parlemeter-2019/executive-summary/en-parlemeter-2019-executive-summary.pdf