https://www.gov.uk/government/news/joint-article-a-deep-and-special-partnership
https://ukandeu.ac.uk/destructive-ambiguity-northern-ireland-the-union-and-the-windsor-framework/
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/uploads/system/uploads/attachment_data/file/637748/Future_customs_arrangements_-_a_future_partnership_paper.pdf