
https://www.iod.com/Portals/0/PDFs/Campaigns%20and%20Reports/Europe%20and%20trade/IoD-Customising-Brexit.pdf?ver=2018-02-15-083137-800

https://publications.parliament.uk/pa/bills/cbill/2017-2019/0005/18005.pdf

https://researchbriefings.files.parliament.uk/documents/CBP-7212/CBP-7212.pdf