http://www.egmontinstitute.be/content/uploads/2019/03/SPB108.pdf?type=pdf
https://www.socialeurope.eu/five-theses-for-a-new-left
http://www.votewatch.eu/blog/alliances-matter-political-networks-the-rule-of-law-principles-and-the-split-of-eu-money-mff/
http://www.ips-journal.eu/regions/europe/article/show/free-spirits-2331/