Zhigeng (Nanjing University of Aeronautics & Astronautics, China) Fang 
Grey Game Theory and Its Applications in Economic Decision-Making [PDF ebook] 

To make the best decisions, you need the best information. However, because most issues in game theory are grey, nearly all recent research has been carried out using a simplified method that considers grey systems as white ones. This often results in a forecasting function that is far from satisfactory when applied to many real situations. Grey Ga