https://institute.global/news/customs-and-exiting-european-union
http://www.automotivecouncil.co.uk/wp-content/uploads/sites/13/2017/06/Automotive-Council-UK-local-sourcing-content-research-2017-Final-1.pdf
https://ec.europa.eu/commission/sites/beta-political/files/outline_of_the_political_declaration.pdf
https://www.wto.org/english/tratop_e/envir_e/trade-climate-change_info_brief_no7_e.pdf