Stine et al. (2009)
Also: Stine et al. 2009
Changes in the phase of the annual cycle of surface temperature
Stine, A. R., Huybers, P. & Fung, I. Y. (2009). Changes in the phase of the annual cycle of surface temperature. Nature. 457(7228),435-440. PDF
https://doi.org/10.1038/nature07675
References
All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.