http://www.cesifo-group.de/ifoHome/publications/working-papers/CESifoWP/CESifoWPdetails?wp_num=6430&CESifoWP.search=+
http://www.iata.org/whatwedo/Documents/economics/impact_of_brexit.pdf
http://www.iata.org/publications/economic-briefings/value-of-air-cargo-2016-summary.pdf
https://www.wto.org/english/res_e/reser_e/ersd201704_e.pdf
https://ec.europa.eu/agriculture/sites/agriculture/files/external-studies/2016-bilateral-trade-agreements/exec-sum_en.pdf
http://ec.europa.eu/transport/sites/transport/files/eu_air_carriers_by_country_holding_an_active_operating_licence.pdf
http://ec.europa.eu/transport/sites/transport/files/pocketbook2016.pdf
http://www.ips-journal.eu/topics/european-union/article/show/eu-assurance-co-2037/