
https://publications.parliament.uk/pa/cm201719/cmselect/cmpubacc/401/401.pdf

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/836116/Explanatory_Note_Accessible.pdf

https://ukandeu.ac.uk/long-read/the-protocol-post-brexit-northern-ireland/?mc_cid=9de7c359e6&mc_eid=815b1928ec