Barnett, T., Zwiers, F., Hengerl, G., Allen, M., Crowly, T., Gillett, N., Hasselmann, K., Jones, P., Santer, B., Schnur, R., Scott, P., Taylor, K., and Tett, S.: Detecting and Attributing External Influences on the Climate System: A Review of Recent Advances, J Climate, 18, 1291–1314, https://doi.org/10.1175/jcli3329.1, 2005.