https://www.dw.com/en/germanys-economic-time-bomb-the-labor-crisis/a-65522919
https://euagenda.eu/upload/publications/untitled-111339-ea.pdf
https://www.esri.ie/system/files/publications/JR1.pdf
http://www.geog.qmul.ac.uk/media/geography/docs/research/working-beyond-the-border/Governing-Labour-Standards.pdf