Hawkins, Ed & Phil Jones (2013) "On increasing global temperatures: 75 years after Callendar", Quarterly Journal of the Royal Meteorological Society, doi: 10.1002/qj.2178
Callendar, G. S. (1938) "The artificial production of carbon dioxide and its influence on temperature", Quarterly Journal of the Royal Meteorological Society, doi: 10.1002/qj.49706427503