https://ec.europa.eu/commission/publications/position-paper-essential-principles-citizens-rights_en
https://fabiusmaximus.com/2016/10/16/stratfor-eu-budget-battles-after-brexit/
https://www.instituteforgovernment.org.uk/explainers/eu-withdrawal-bill-amendments-and-debates
https://hansard.parliament.uk/commons/2018-03-07/debates/65828E0C-3CC7-43AE-B5D2-B5F1B5D42A4C/EuropeanUnionCitizenship