http://www.niesr.ac.uk/sites/default/files/publications/NIESR%20EU2%20MIGRATION%20REPORT.pdf
http://www.consilium.europa.eu/en/press/press-releases/2017/04/29-euco-brexit-guidelines/
http://ourglobalfuture.com/wp-content/uploads/2017/05/Global-Future-The_case_for_immigration.pdf
https://publications.parliament.uk/pa/cm201719/cmselect/cmhaff/961/961.pdf