
https://www.consilium.europa.eu/media/ny3j24sm/much-more-than-a-market-report-by-enrico-letta.pdf

http://www.egmontinstitute.be/content/uploads/2019/03/SPB108.pdf?type=pdf

https://ec.europa.eu/commission/presscorner/api/files/document/print/ov/speech_22_5493/SPEECH_22_5493_OV.pdf