
http://www.morganstanley.com/ideas/global-trade-protectionism

https://www.europarl.europa.eu/meetdocs/2009_2014/documents/deea/dv/2203_07/2203_07en.pdf

https://www.open-britain.co.uk/new_research_trade_deals_with_five_key_countries_could_take_26_years_to_negotiate