
https://www.europarl.europa.eu/meetdocs/2009_2014/documents/deea/dv/2203_07/2203_07en.pdf

http://www.iata.org/publications/economic-briefings/value-of-air-cargo-2016-summary.pdf

http://www.sussex.ac.uk/spru/newsandevents/2017/publications/food-brexit