http://odlisnost.cz/posts/pristehovalci-a-nase-zamestnani
https://www.esri.ie/system/files/publications/JR1.pdf
https://www.gov.uk/guidance/status-of-eu-nationals-in-the-uk-what-you-need-to-know
http://www.ilo.org/wcmsp5/groups/public/—dgreports/—dcomm/—publ/documents/publication/wcms_537982.pdf