https://www.bloomberg.com/news/articles/2019-09-11/world-s-oldest-customs-union-and-u-k-reach-a-post-brexit-deal
http://ukandeu.ac.uk/for-the-third-time-we-surveyed-mps-on-their-attitude-to-brexit-and-the-results-were-fascinating/
https://publications.parliament.uk/pa/ld201719/ldselect/ldeucom/63/63.pdf