https://www.hks.harvard.edu/sites/default/files/centers/mrcbg/working.papers/84_Harvard%20Working%20PaperTime%20for%20ClarityFinPAS.pdf
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.publications.parliament.uk/pa/ld201617/ldselect/ldeucom/78/78.pdf