https://ec.europa.eu/commission/sites/beta-political/files/customs_controls_0.pdf
https://www.rand.org/pubs/research_reports/RR2200.html
http://cer.eu/in-the-press/speech-michel-barnier-future-eu-conference
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