https://www.esri.ie/system/files/publications/SUSTAT117.pdf
http://www.fdf.org.uk/news.aspx?article=8062
https://www.open-britain.co.uk/new_research_trade_deals_with_five_key_countries_could_take_26_years_to_negotiate
https://www.wto.org/english/res_e/booksp_e/gvc_dev_report_2019_e.pdf