This study quantifies the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996–2005.
MEKONNEN, M.M. ; HOEKSTRA, A.Y. (2011): The Green, Blue and Grey Water Footprint of Crops and Derived Crop Products. In: Hydrology and Earth System Sciences: Volume 15 , 1577-1600. URL [Accessed: 09.09.2013]