https://ec.europa.eu/commission/sites/beta-political/files/customs_controls_0.pdf
https://ukandeu.ac.uk/the-uk-internal-market-bill-breaking-law-and-reputation/?mc_cid=7627d659c2&mc_eid=815b1928ec
https://publications.parliament.uk/pa/cm201719/cmselect/cmbeis/380/380.pdf
https://www.opendemocracy.net/uk/peter-geoghegan/growing-up-on-border-on-brexit-s-irish-problem?utm_source=Daily+Newsletter&utm_campaign=b906170335-DAILY_NEWSLETTER_MAILCHIMP&utm_medium=email&utm_term=0_717bc5d86d-b906170335-407405485