https://www.opendemocracy.net/en/beyond-trafficking-and-slavery/exploitation-rule-not-exception/
https://www.gov.uk/guidance/status-of-eu-nationals-in-the-uk-what-you-need-to-know
https://www.economiesuisse.ch/de/artikel/kuendigungsinitiative-ii-eine-wohlstandsbremse-par-excellence
https://www.unhcr.org/5ee200e37.pdf