https://www.baua.de/DE/Angebote/Publikationen/Berichte/F2398.pdf?__blob=publicationFile&v=3
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/648148/September_-_Joint_technical_note_on_the_comparison_of_EU-UK_positions_on_citizens__rights.pdf
http://www.euronews.com/2017/09/28/posted-workers-facing-harsh-realities?utm_source=newsletter&utm_medium=en&utm_content=posted-workers-facing-harsh-realities&_ope=eyJndWlkIjoiZjU3Y2JhYmUwMGUxZDFiNTUxOTU1ZDljNzExNTI1MmEifQ==
https://www.parlament.cat/document/cataleg/48146.pdf
http://www.case-research.eu/files/?id_plik=5223
http://www.ladocumentationfrancaise.fr/var/storage/rapports-publics/084000459.pdf
http://www.institutdelors.eu/media/europeidentitemythes-bouchard-ijd-dec16.pdf?pdf=ok
http://www.congreso.es/consti/constitucion/indice/titulos/articulos.jsp?ini=155&tipo=2
http://www.institutdelors.eu/media/publicpoliciestopromoteventurecapital-stnder-august17.pdf?pdf=ok
http://www.ladocumentationfrancaise.fr/var/storage/rapports-publics/174000710.pdf