https://www.nao.org.uk/wp-content/uploads/2017/07/The-Customs-Declaration-Service.pdf
http://uk.businessinsider.com/lengthy-transition-kill-off-brexit-young-voters-corbyn-may-2017-8?r=US&IR=T
https://ukandeu.ac.uk/northern-irelands-vicious-cycle-of-governance-failure/