
https://blogs.lse.ac.uk/brexit/2019/10/09/northern-ireland-depends-on-the-eus-fluid-borders-for-survival/

http://www.epc.eu/documents/uploads/pub_7576_northernirelandandbrexit.pdf

http://www.express.co.uk/news/uk/840143/DNA-English-villages-foreigners-residents-study