Thenkabail, P. S., J. W. Knox, M. Ozdogan, M. K. Gumma, R. G. Congalton, Z. Wu, C. Milesi, A. Finkral, and M. Marshall (2012), Assessing future risks to agricultural productivity, water resources and food security: how can remote sensing help?, Photogrammetric Engineering and Remote Sensing, 78, 773-782.