https://theconversation.com/eu-citizens-proposal-a-lawyer-examines-the-detail-80111
https://www.socialeurope.eu/brexit-shows-us-real-first-world-problems-look-like
https://theconversation.com/why-the-eus-singapore-ruling-does-not-lead-to-a-smoother-brexit-road-for-britain-78116
https://www.rand.org/pubs/research_reports/RR2200.html