https://www.socialeurope.eu/the-end-of-the-liberal-west
http://blogs.lse.ac.uk/brexit/2018/11/23/hubert-butler-essay-prize-what-happened-to-europe-without-frontiers/
http://www.cer.org.uk/sites/default/files/insight_AG_CO_18.5.17.pdf
https://visegradinsight.eu/distant-liaisons-france-central-europe/