https://www.acams.org/en/media/document/russia-sanctions-evasion-key-methods-and-techniques-part-1
http://ec.europa.eu/transport/sites/transport/files/eu_air_carriers_by_country_holding_an_active_operating_licence.pdf
https://www.imf.org/external/pubs/ft/fandd/2020/06/long-term-economic-impact-of-pandemics-jorda.htm
https://geoii.eu/start