http://www.oxera.com/Latest-Thinking/Publications/Reports/2017/Brexit-ports.aspx
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/224244/evidence-british-influence.pdf
https://www.gov.uk/government/news/joint-article-a-deep-and-special-partnership
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/728135/THE_FUTURE_UK-EU_RELATIONSHIP.pdf