Cleland, E. E., Smith, M. D., Andelman, S. J., Bowles, C., Carney, K. M., Horner-Devine, M. C., Drake, J. M., Emery, S. M., Gramling, J., and Vandermast, D. B. 2004. "Invasion in space and time: non-native species richness and relative abundance respond to interannual variation in productivity and diversity." Ecology Letters, 7 947–957.