
https://visegradinsight.eu/perfect-storm-covid19-eurosceptic-poland-hungary/

http://www.cesifo-group.de/portal/page/portal/DocBase_Service/studien/Studie-2017-Felbermayr-etal-Brexit-79843.pdf

http://news.sky.com/story/theresa-may-theres-no-economic-case-for-breaking-up-the-uk-10787816