http://www.consilium.europa.eu/en/press/press-releases/2017/04/29-euco-brexit-guidelines/
http://oegfe.at/wordpress/2017/05/the-free-movement-of-workers-within-the-eu-and-the-case-of-austria-balancing-distortions-and-adding-value-op-ed-paul-schmidt-the-european-financial-review/
https://www.gisreportsonline.com/r/sweden-immigrants-crisis/
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/695321/An_inspection_of_exit_checks.pdf