https://ec.europa.eu/commission/sites/beta-political/files/position-paper-public-procurement_en.pdf
https://www.esri.ie/system/files/publications/SUSTAT117.pdf
https://www.theguardian.com/politics/2017/sep/04/uk-trade-deals-after-brexit-theresa-may-eu
http://www.cer.eu/sites/default/files/bulletin_118_js-sl_article2.pdf