https://www.socialeurope.eu/why-such-disparity-between-unemployment-rates-in-europe
http://ftp.iza.org/dp11249.pdf
https://www.economiesuisse.ch/de/artikel/immerhin-zugang-zu-arbeitskraeften-aus-drittstaaten-gesichert
https://www.wsi.de/download-proxy-for-faust/download-pdf?url=http%3A%2F%2F217.89.182.78%3A451%2Fabfrage_digi.fau%2Fp_wsi_report_63e_2021.pdf%3Fprj%3Dhbs-abfrage%26ab_dm%3D1%26ab_zeig%3D9200%26ab_diginr%3D8483