https://www.publications.parliament.uk/pa/cm201617/cmselect/cmintrade/817/817.pdf
https://ec.europa.eu/commission/sites/beta-political/files/citizens-rights-essential-principles-draft-position-paper_en.pdf
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/680185/Governor_letter_to_CX_-_Feb_2018.pdf