
https://ukandeu.ac.uk/wp-content/uploads/2019/12/Brexit-the-manifestos-uncovered.pdf

https://openeurope.org.uk/today/blog/what-would-a-no-deal-after-the-transition-period-look-like/

http://data.parliament.uk/writtenevidence/committeeevidence.svc/evidencedocument/treasury-committee/the-uks-economic-relationship-with-the-european-union/oral/72053.html