Gillett, N.P., Stone, D.A., Stott, P.A., Nozawa, T., Karpechko, A.Y., Hegerl, G.C., Wehner, M.F., and Jones, P.D., 2008
Attribution of polar warming to human influence.
Nature Geoscience, 1, doi:10.1038/ngeo338
Zhang, X., Zwiers, F.W., Hegerl, G.C., Lambert, F.H., Gillett, N.P., Solomon, S., Stott, P.A., and Nozawa, T., 2007
Detection of human influence on 20th century precipitation trends.
Nature, 448 461-465