https://fpc.org.uk/wp-content/uploads/2022/04/London-Calling-publication-April-2022.pdf
https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32019R0452&from=EN
http://ec.europa.eu/transport/sites/transport/files/eu_air_carriers_by_country_holding_an_active_operating_licence.pdf
https://piie.com/system/files/documents/2018-06-27-rosengren-presentation.pdf