https://www.publications.parliament.uk/pa/cm201617/cmselect/cmexeu/1125/1125.pdf
https://carnegieendowment.org/politika/88202
https://www.destatis.de/DE/PresseService/Presse/Pressemitteilungen/2017/08/PD17_261_12511pdf.pdf?__blob=publicationFile
https://www.opendemocracy.net/uk/jeremy-gilbert/forty-years-of-failure-how-to-challenge-narrative-of-hard-brexit