
http://www.lawyersforbritain.org/eu-deal-financial-liabilities.shtml

https://www.sussex.ac.uk/webteam/gateway/file.php?name=briefing-paper-1.pdf&site=18

https://blogs.lse.ac.uk/brexit/2019/10/09/northern-ireland-depends-on-the-eus-fluid-borders-for-survival/