http://blogs.lse.ac.uk/brexit/2017/07/05/bloody-difficult-britain-has-already-blown-its-chances-of-a-good-deal-from-the-eu27/
https://www.cer.eu/sites/default/files/insight_SL_5.11.19_2.pdf
https://ukandeu.ac.uk/wp-content/uploads/2020/03/Parliament-and-Brexit-report.pdf