http://www.cer.eu/sites/default/files/bulletin_118_js-sl_article2.pdf
https://www.esri.ie/system/files/publications/RB202017_2.pdf
http://sydneydemocracynetwork.org/article-brexit-yes-will-suffer-well/
https://ec.europa.eu/commission/sites/beta-political/files/aviation.pdf