https://ec.europa.eu/competition/publications/reports/kd0419345enn.pdf
http://openeurope.org.uk/today/blog/will-brexit-ground-flights-europe/
https://www.frc.org.uk/news/july-2020/frc-principles-for-operational-separation-of-a-(1)
https://ec.europa.eu/newsroom/dae/redirection/document/78778