http://www.rug.nl/research/portal/files/41711829/cesifo1_wp6448.pdf
https://ec.europa.eu/info/sites/info/files/com-2018-890-final.pdf
https://ec.europa.eu/commission/sites/beta-political/files/position-paper-public-procurement_en.pdf
https://www.politico.eu/article/time-for-brexit-reckoning-uk-eu-relationship/