
https://www.politico.eu/wp-content/uploads/2021/11/15/2021.11.15-Letter-to-EC-on-quality-of-replies-to-parliamentary-questions.pdf

https://www.bruegel.org/system/files/2024-05/WP%2013%202024.pdf

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