Wada, Y. ., van Beek, L. ., van Kempen, C. M., Reckman, J. W. T. M., Vasak, S. ., & Bierkens, M. . (2010). Global depletion of groundwater resources. Geophysical Research Letters, 37, 20402. http://doi.org/10.1029/2010GL044571 (Original work published October 2010)