Usoskin et al. (2005)
Also: Usoskin et al. 2005, Usoskin 2005
Solar activity over the last 1150 years: does it correlate with climate?
Usoskin, I. G., Schüssler, M., Solanki, S. K., & Mursula, K. (2005, March). Solar activity over the last 1150 years: does it correlate with climate?. In 13th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun (Vol. 560, p. 19). Link to paper
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.