http://www.consilium.europa.eu/en/press/press-releases/2017/04/29-euco-brexit-guidelines/
https://www.wilsoncenter.org/sites/default/files/media/uploads/documents/RAFDI_Working_Group_Report_0.pdf
https://www.brookings.edu/blog/the-avenue/2017/08/03/u-s-immigration-levels-continue-to-fuel-most-community-demographic-gains/?utm_campaign=Brookings%20Brief&utm_source=hs_email&utm_medium=email&utm_content=54956018
https://openmigration.org/en/op-ed/how-immigrants-are-saving-the-italian-economy-and-pensions/