https://publications.parliament.uk/pa/cm201719/cmselect/cmworpen/848/848.pdf
https://www.cer.eu/sites/default/files/insight_SL_5.11.19_2.pdf
https://www.publications.parliament.uk/pa/ld201617/ldselect/ldeucom/169/169.pdf
https://www.opendemocracy.net/en/opendemocracyuk/customs-union-leaves-everything-play-trade-justice/?utm_source=Daily+Newsletter&utm_campaign=f531c721c4-DAILY_NEWSLETTER_MAILCHIMP&utm_medium=email&utm_term=0_717bc5d86d-f531c721c4-407405485