http://www.guengl.eu/uploads/news-documents/Working_paper_Border_controls_on_cross_border_trade_in_goods.pdf
https://ustr.gov/sites/default/files/files/Press/Reports/2018%20National%20Trade%20Estimate%20Report.pdf
https://www.timeshighereducation.com/fr/books/review-shadows-empire-anglosphere-british-politics-michael-kenny-and-nick-pearce-polity-press
http://blogs.lse.ac.uk/brexit/2017/10/24/the-eu-isnt-protectionist-its-one-of-the-most-open-economies-in-the-world/
https://www.open-britain.co.uk/new_research_trade_deals_with_five_key_countries_could_take_26_years_to_negotiate
https://www.cesifo-group.de/DocDL/ifoDD_18-01_29-31_Achten.pdf
http://blogs.worldbank.org/developmenttalk/wto-s-trade-facilitation-agreement-and-doing-business-reforms-are-they-related-and-how
https://publications.parliament.uk/pa/cm201719/cmselect/cmintrade/520/520.pdf
https://publications.parliament.uk/pa/cm201719/cmselect/cmbeis/379/379.pdf
https://blogs.sussex.ac.uk/uktpo/2018/02/15/sustainability-impact-assessment-for-post-brexit-britain/