http://www.independent.co.uk/news/uk/politics/article-127-brexit-stop-what-is-it-single-market-eu-eea-theresa-may-article-50-a7955806.html
https://ec.europa.eu/commission/publications/position-paper-transmitted-eu27-ongoing-police-and-judicial-cooperation-criminal-matters_en
http://ukandeu.ac.uk/cancelling-brexit-what-would-happen-if-we-changed-our-mind-about-leaving-the-eu/