
https://www.hks.harvard.edu/sites/default/files/centers/mrcbg/programs/senior.fellows/Brexit%20Paper%20IV%20-%20Final%20Paper.pdf

https://www.tuc.org.uk/news/cbi-and-tuc-call-prime-minister-change-brexit-approach?language=cy

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/710147/DATA_-_FINAL.pdf