
http://www.diw.de/documents/publikationen/73/diw_01.c.562050.de/17-29.pdf

https://www.conservativehome.com/parliament/2018/07/our-brexit-plan-takes-back-control-of-money-laws-and-borders-and-heres-how-may-and-raabs-letter-to-conservative-mps.html

https://socialeurope.eu/brexit-why-does-northern-ireland-matter-so-much