
http://www.coggs.polis.cam.ac.uk/news/forum-on-geopolitics-triple-bill-on-brexit

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

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