https://www.eurofound.europa.eu/sites/default/files/ef_publication/field_ef_document/ef1663en.pdf
https://www.strategie.gouv.fr/sites/strategie.gouv.fr/files/atoms/files/fs-2020-dt-organisations-du-travail-avril.pdf
https://www.boe.es/boe/dias/2021/12/30/pdfs/BOE-A-2021-21788.pdf
http://www.britishchambers.org.uk/press-office/press-releases/bcc-firms-invest-in-local-labour-but-still-need-foreign-skills-to-plug-shortages.html