https://ec.europa.eu/commission/sites/beta-political/files/guiding-principles-dialogue-ei-ni_en.pdf
https://www.instituteforgovernment.org.uk/sites/default/files/publications/5704%20IFG%20-%20Frictionless%20Trade%20Web.pdf
https://waitingfortax.com/2017/05/29/sometimes-you-try-and-you-do-not-succeed/?cmpid=BBBXT053017_BIZ&utm_medium=email&utm_source=newsletter&utm_term=170530&utm_campaign=brexit
http://www.guengl.eu/news/article/eu-citizens-rights-and-status-of-north-of-ireland-must-be-prioritised-in-br