APA

Helm D. ., Helm D. & Hepburn C. . (2009). The economics and politics of climate change. New York: Oxford University Press.

Chicago

Helm Dieter, Helm Dieter and Hepburn Cameron. 2009. The economics and politics of climate change. New York: Oxford University Press.

Harvard

Helm D. ., Helm D. and Hepburn C. . (2009). The economics and politics of climate change. New York: Oxford University Press.

MLA

Helm Dieter, Helm Dieter and Hepburn Cameron. The economics and politics of climate change. New York: Oxford University Press. 2009.