https://www.baua.de/DE/Angebote/Publikationen/Berichte/F2398.pdf?__blob=publicationFile&v=3
https://www.instituteforgovernment.org.uk/sites/default/files/publications/coronavirus-unemployment-five-nation-comparison.pdf
https://www.ilo.org/legacy/english/inwork/cb-policy-guide/declarationofPhiladelphia1944.pdf
https://www.cesifo-group.de/DocDL/ifoDD_18-01_03-09_Ochsner.pdf