https://www.gov.uk/guidance/status-of-eu-nationals-in-the-uk-what-you-need-to-know
https://www.rand.org/pubs/research_reports/RR2200.html
https://www.gov.uk/government/news/pms-european-council-press-statement-20-october-2017
https://theconversation.com/mary-beard-is-right-roman-britain-was-multi-ethnic-so-why-does-this-upset-people-so-much-82269