http://fedtrust.co.uk/our-work-on-europe/hard-brexit-international-trade-and-the-wto-scenario/
https://policyexchange.org.uk/wp-content/uploads/2017/06/Defying-Gravity-A-critique-of-estimates-of-the-economic-impact-of-Brexit.pdf
https://www.gov.uk/government/news/david-davis-teesport-speech-implementation-period-a-bridge-to-the-future-partnership-between-the-uk-eu