https://publications.parliament.uk/pa/cm201719/cmselect/cmbeis/380/380.pdf
https://www.instituteforgovernment.org.uk/printpdf/10590
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/650455/customs_bill_white_paper_print.pdf
https://ukandeu.ac.uk/trade-migration-and-brexit/