https://ukandeu.ac.uk/wp-content/uploads/2019/12/Brexit-the-manifestos-uncovered.pdf
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/728135/THE_FUTURE_UK-EU_RELATIONSHIP.pdf
http://blogs.sussex.ac.uk/uktpo/files/2017/11/Briefing-Paper-11.pdf
https://www.cnas.org/publications/podcast/luke-coffey-on-brexit-and-the-future-of-the-special-relationship