Helm, D. (2005). Climate-Change Policy: Introduction. Oxford University Press.
Chicago-čujuhus (17. p.)Helm, D. Climate-Change Policy: Introduction. Oxford University Press, 2005.
MLA-čujuhus (9. p.)Helm, D. Climate-Change Policy: Introduction. Oxford University Press, 2005.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.