http://www.niesr.ac.uk/sites/default/files/publications/NIESR%20EU2%20MIGRATION%20REPORT.pdf
https://rusi.org/explore-our-research/publications/commentary/giving-raf-typhoons-ukraine-would-be-very-expensive-symbolic-gesture
https://www.legislation.gov.uk/uksi/2020/680/pdfs/uksiem_20200680_en.pdf