https://publications.parliament.uk/pa/cm201719/cmselect/cmhaff/421/421.pdf
https://www.nao.org.uk/wp-content/uploads/2017/07/The-Customs-Declaration-Service.pdf
https://leftfootforward.org/2016/04/majority-of-young-people-support-eu-membership-but-half-might-not-even-vote/
http://www.res.org.uk/view/art4Apr17Features.html