http://blogs.lse.ac.uk/brexit/2018/09/25/brexit-has-become-unnegotiable-theresa-may-has-a-constitutional-duty-to-admit-that-truth/
https://www.niauk.org/media-centre/blog/uk-explore-retaining-membership-euratom/
http://www.ecfr.eu/page/-/ECFR-_245_-_Crisis_and_Cohesion_-_A_10_Year_Review_Janning_WEB.pdf