
https://www.sbs.strath.ac.uk/economics/fraser/20171129/GMB-Brexit-report.pdf

https://ec.europa.eu/commission/sites/beta-political/files/customs_controls_0.pdf

https://ukandeu.ac.uk/why-david-cameron-called-the-2016-referendum/?mc_cid=dcb6ed542c&mc_eid=815b1928ec