http://fedtrust.co.uk/the-2017-general-election-a-mandate-for-brexit/
https://ec.europa.eu/commission/sites/beta-political/files/outline_of_the_political_declaration.pdf
http://www.cesifo-group.de/ifoHome/publications/working-papers/CESifoWP/CESifoWPdetails?wp_num=6448&CESifoWP.search=+
http://www.ecfr.eu/article/commentary_there_is_life_for_the_eu_after_brexit