https://ukandeu.ac.uk/wp-content/uploads/2021/11/Brexit-and-Services-Trade-Working-Paper.pdf
http://www.ecb.europa.eu/pub/pdf/other/ebart201703_01.en.pdf
https://www.opendemocracy.net/en/oureconomy/rethinking-world-trade-organisation/?utm_source=Daily+Newsletter&utm_campaign=d3b2767bfc-DAILY_NEWSLETTER_MAILCHIMP&utm_medium=email&utm_term=0_717bc5d86d-d3b2767bfc-407405485
https://www.nao.org.uk/wp-content/uploads/2017/07/The-Customs-Declaration-Service.pdf