http://www.ecreu.com/pdfs/alternative-white-paper-presented-by-UK-%20citizens-in-europe.pdf
https://www.epp.eu/files/uploads/2017/04/11-EPP-Resolution-1-2.pdf
https://reliefweb.int/attachments/66a09358-2cf3-448c-846a-d29f9f8f768c/62a9d1494.pdf
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/695321/An_inspection_of_exit_checks.pdf