Hansen et al. (1997)
Also: Hansen et al. 1997
Radiative forcing and climate response
Hansen, J., Sato, M. & Ruedy, R. (1997). Radiative forcing and climate response. Journal of Geophysical Research: Atmospheres. 102(D6),6831-6864. PDF
https://doi.org/10.1029/96jd03436
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.