https://www.nao.org.uk/wp-content/uploads/2018/01/Implementing-the-UKs-exit-from-the-European-Union-the-Deparment-for-International-Trade.pdf
https://institute.global/sites/default/files/articles/Fixing-the-Northern-Ireland-Protocol-A-Way-Forward.pdf
https://eupinions.eu/index.php?id=12463