@Article{hess-10-443-2006,
AUTHOR = {Yang, H. and Wang, L. and Abbaspour, K. C. and Zehnder, A. J. B.},
TITLE = {Virtual water trade: an assessment of water use efficiency in the international food  trade},
JOURNAL = {Hydrology and Earth System Sciences},
VOLUME = {10},
YEAR = {2006},
NUMBER = {3},
PAGES = {443--454},
URL = {http://www.hydrol-earth-syst-sci.net/10/443/2006/},
ISSN = {1027-5606}
}