Simmons, A.J., Jones, P.D., da Costa Bechtold, V., Beljaars, A.C.M., Kallberg, Saarinen, S., Uppala, S.M., Viterbo, P. and Wedi, N., 2004
“Comparison of trends and low-frequency variability in CRU, ERA-40, and NCEP/NCAR analyses of surface air temperature.”
Journal of Geophysical Research 109, doi:10.1029/2004JD005306, D24115 American Geophysical Union (R)
(keywords: trends variability surface air temperature)