https://ukandeu.ac.uk/wp-content/uploads/2021/11/Brexit-and-Services-Trade-Working-Paper.pdf
http://www.resolutionfoundation.org/app/uploads/2017/10/Changing-Lanes-3.pdf
https://publications.parliament.uk/pa/ld201719/ldselect/ldeucom/15/15.pdf
https://www.instituteforgovernment.org.uk/sites/default/files/publications/IfG_Brexit_customs_WEB.pdf