https://www.boeckler.de/pdf/p_imk_report_152e_2020.pdf
https://www.greatbritishpolitics.co.uk/europe/654-dual-nationality-and-the-hurdles-facing-britons-who-want-to-keep-eu-citizenship-after-brexit.html
https://cepr.org/sites/default/files/policy_insights/PolicyInsight91.pdf
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwij8PLy0aH1AhVEhP0HHf7rAYwQFnoECAYQAQ&url=https%3A%2F%2Fassets.gov.ie%2F203426%2F468690ef-2b01-4d7d-a6d3-c0cbabcab3cb.pdf&usg=AOvVaw2-vnoHbS5dgbnNXNla3sLK