https://www.hesa.ac.uk/data-and-analysis/publications/finances-2015-16/introduction
http://www.msz.gov.pl/en/news/deputy_minister_renata_szczech_takes_part_in_a_debate_on_europe_s_future
https://cthi.taxjustice.net/cthi2021/country-list.pdf
https://www.bruegel.org/wp-content/uploads/2021/05/PC-2021-11-ecofin-210521.pdf