https://committees.parliament.uk/publications/4976/documents/50058/default/
https://www.oecd-ilibrary.org/docserver/7e1bf673-en.pdf?expires=1537041018&id=id&accname=guest&checksum=E2E4B144ED9C13DF58246370C7677883
https://www.assemblee-nationale.fr/dyn/16/rapports/cion_fin/l16b1678_rapport-information#
http://blogs.lse.ac.uk/brexit/2017/07/06/the-1bn-bung-wont-protect-northern-ireland-from-the-pain-of-a-hard-brexit/