https://www.gov.uk/guidance/status-of-eu-nationals-in-the-uk-what-you-need-to-know
https://www.bertelsmann-stiftung.de/de/themen/aktuelle-meldungen/2019/maerz/brexit-kostet-deutschland-bis-zu-zehn-milliarden-euro-jaehrlich/
https://ukandeu.ac.uk/increased-immigration-from-non-eu-countries-not-just-a-british-phenomenon/
https://www.cer.eu/sites/default/files/insight_JS_JP_17.1.23.pdf