What really happened when Swedes tried six-hour days? Useful article for  A Level Economics for  http://www.bbc.co.uk/news/business-38843341
Edexcel spec references
3.5.1 a Factors that influence the demand for labour
3.5.3 b Understanding current labour market issues
AQA spec reference
4.1.6.1 The demand for labour, marginal productivity theory