Folland, C.K., Rayner, N.A., Brown, S.J., Smith, T.M., Shen, S.S.P., Parker, D.E., Macadam, I., Jones, P.D. and others., 2001
Global temperature change and its uncertainties since 1861.
Geophysical Research Letters 28, 2621-2624
(keywords: temperature global historical trends statistics warming climate change)