https://dailynewshungary.com/mayors-of-v4-countries-capitals-sign-pact-of-free-cities/
https://www.socialeurope.eu/2017/06/eu-fateful-year-2017/
http://www.europarl.europa.eu/sides/getDoc.do?pubRef=-%2F%2FEP%2F%2FNONSGML%2BCOMPARL%2BPE-602.995%2B01%2BDOC%2BPDF%2BV0%2F%2FEN