https://ukandeu.ac.uk/increased-immigration-from-non-eu-countries-not-just-a-british-phenomenon/
https://ippedico.github.io/website/ABIP_entrepreneurship_drain.pdf
http://library.fes.de/pdf-files/id/ipa/13354.pdf
https://www.socialeurope.eu/2017/06/theresa-mays-other-citizens-of-nowhere/