
https://ec.europa.eu/commission/sites/beta-political/files/citizens-rights-essential-principles-draft-position-paper_en.pdf

http://www.cesifo-group.de/ifoHome/publications/working-papers/CESifoWP/CESifoWPdetails?wp_num=6438&CESifoWP.search=+

http://www.britishchambers.org.uk/press-office/press-releases/bcc-no-deal-not-an-option-for-business-communities.html