As a start here is a link to the pdf version of an article about virtual water policies and struggles in Egypt and India. There is an extensive list of references at the end of the paper.
Roth, Dik, and Jeroen Warner. "Virtual Water: Virtuous impact? The unsteady state of virtual water." Agriculture and Human Values 25 (2008): 257-70. SpringerLink. 3 Oct. 2007. Springer. 20 Feb. 2009
Some notable references:
Hakimian, H. (2003). “Water scarcity and food imports: An empirical investigation of the ‹Virtual Water’ hypothesis in the MENA region.” Occasional Paper No. 46. London, UK: School of Oriental and Asian Studies (SOAS), Water Issues Study Group, University of London. Retrieved from http://www.soas.ac.uk/waterissues/occasionalpapers/OCC46.pdf on November 3, 2006
Wichelns D. (2001). The role of ‹virtual water’ in efforts to achieve food security and other national goals, with an example from Egypt. Agricultural Water Management 49: 131–151