https://www.socialeurope.eu/2017/07/brexit-to-nowhere/
https://www.smmt.co.uk/wp-content/uploads/sites/2/1207-SMMT-position-on-UK-Brexit-negotiations.pdf
https://publications.parliament.uk/pa/cm201719/cmselect/cmpubacc/401/401.pdf
http://www.ecfr.eu/page/-/Keeping_Europe_Safe_After_Brexit2.pdf