
https://publications.parliament.uk/pa/bills/cbill/2019-2020/0007/20007.pdf

http://www.migrationobservatory.ox.ac.uk/resources/reports/unsettled-status-which-eu-citizens-are-at-risk-of-failing-to-secure-their-rights-after-brexit/

https://rusi.org/sites/default/files/newsbrief_37.3_elliott.pdf