https://trade.ec.europa.eu/doclib/docs/2021/september/tradoc_159803.pdf
https://www.wto.org/english/tratop_e/tpr_e/s434_e.pdf
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/637748/Future_customs_arrangements_-_a_future_partnership_paper.pdf
https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:52022PC0457&from=EN