https://wiiw.ac.at/shifting-patterns-of-migration-in-europe-new-source-countries-old-challenges-dlp-6915.pdf
https://www.ajot.com/news/the-brexit-checklist-where-the-u.k.-and-eu-currently-stand
http://library.fes.de/pdf-files/bueros/budapest/15322-20190505.pdf