
https://www.theguardian.com/politics/2017/nov/10/brexit-date-is-not-irreversible-says-man-who-wrote-article-50-lord-kerr

https://ec.europa.eu/commission/publications/position-paper-essential-principles-financial-settlement_en

http://fedtrust.co.uk/our-work-on-europe/brexit-heading-to-a-deal-or-no-deal-while-uk-politics-implodes/