
https://policyscotland.gla.ac.uk/blog-sir-ivan-rogers-speech-text-in-full/

https://www.hks.harvard.edu/sites/default/files/centers/mrcbg/programs/senior.fellows/Brexit%20Paper%20IV%20-%20Final%20Paper.pdf

http://www.britishchambers.org.uk/press-office/press-releases/bcc-open-letter-to-pm-businesses-need-clarity-on-brexit.html