https://www.wto.org/english/res_e/booksp_e/wtr23_e/wtr23_e.pdf
https://openeurope.org.uk/today/blog/what-would-a-no-deal-after-the-transition-period-look-like/
https://www.iai.it/sites/default/files/iai1910.pdf
http://blogs.sussex.ac.uk/uktpo/files/2017/11/Briefing-Paper-11.pdf