A useful article for a level economics – http://www.bbc.co.uk/news/business-43459153 and where to find the relevant section in the spec for Edexcel, AQA & OCR:
Edexcel spec reference 4.1.6 – Impact of protectionist policies on consumers
AQA spec reference 4.2.6.2 – The nature of protectionist policies, such as: tariffs, quotas and export subsidies.
OCR spec reference P 25 – Evaluate the case for and against free trade