Yohe, G.W.; et al. (2007). "20.6 Global and aggregate impacts; 20.6.1 History and present state of aggregate impact estimates". In M.L. Parry; et al. (eds.). Perspectives on climate change and sustainability. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. Archived from the original on 2011-11-07. Retrieved 2011-10-12.
Yohe, G.W.; et al. (2007). "20.6 Global and aggregate impacts; 20.6.1 History and present state of aggregate impact estimates". In M.L. Parry; et al. (eds.). Perspectives on climate change and sustainability. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. Archived from the original on 2011-11-07. Retrieved 2011-10-12.