
https://ec.europa.eu/commission/sites/beta-political/files/revised_withdrawal_agreement_including_protocol_on_ireland_and_nothern_ireland.pdf

https://sp-bpr-en-prod-cdnep.azureedge.net/published/2018/2/2/Common-UK-Frameworks-after-Brexit/SB%2018-09.pdf

https://blogs.lse.ac.uk/brexit/2019/10/23/long-read-the-makings-of-brexit-and-the-road-ahead/