https://www.eurofound.europa.eu/sites/default/files/ef_publication/field_ef_document/ef1714en.pdf
https://www.cesifo-group.de/DocDL/ifoDD_18-01_03-09_Ochsner.pdf
https://www.eurofound.europa.eu/sites/default/files/ef_publication/field_ef_document/ef1708en.pdf
https://www.instituteforgovernment.org.uk/sites/default/files/publications/IFGJ5327_Report_Brexit_Civil_Service_080317_WEB.pdf