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

https://ukandeu.ac.uk/explainers/the-protocol-on-ireland-northern-ireland/?mc_cid=2bd4dc8e93&mc_eid=815b1928ec

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/650455/customs_bill_white_paper_print.pdf