citation
Cassman, K. G.; Wood, S.; Choo, P. S.; Cooper, H. D.; Devendra, C.; Dixon, J.; Gaskell, J.; Khan, S.; Lal, R.; Lipper, Leslie; Pretty, J.; Primavera, J.; Ramankutty, N.; Viglizzo, E.; Wiebe, K.; Kadungure, S.; Kanbar, N.; Khan, Z.; Leakey, R.; Porter, S.; Sebastian, K.; Tharme, Rebecca. 2005. Cultivated systems. In Hassan, R.�; Scholes, R.�; Ash, N. (Eds.).� Ecosystems and human well-being: current state and trends. Volume 1.� Washington, DC, USA: Island Press. pp.745-794.