https://hansard.parliament.uk/commons/2018-03-07/debates/65828E0C-3CC7-43AE-B5D2-B5F1B5D42A4C/EuropeanUnionCitizenship
https://ec.europa.eu/commission/sites/beta-political/files/financial-settlement-essential-principles-draft-position-paper_en.pdf
https://ec.europa.eu/commission/publications/position-paper-essential-principles-financial-settlement_en