1. Abbott, W.N.: 1955, Variation of the absolute surface brightness in the corona with the solar cycle. Ann. Astrophys. 18, 81. ADS .
2. Allen, C.W.: 1973, Astrophysical Quantities, 3rd edn. Athlone Press, London, 176. ADS .
3. Altrock, R.C.: 2013, Forecasting the maxima of solar cycle 24 with coronal Fe xiv emission. Solar Phys. 289, 623. DOI .
4. Ball, W.T., Unruh, Y.C., Krivova, N.A., Solanki, S., Wenzler, T., Mortlock, D.J., Jaffe, A.H.: 2012, Reconstruction of total solar irradiance 1974 – 2009. Astron. Astrophys. 541, A27. DOI .
5. Basu, S., Broomhall, A.M., Chaplin, W.J., Elsworth, Y.: 2012, Thinning of the Sun’s magnetic layer: The peculiar solar minimum could have been predicted. Astrophys. J. 758, 43. DOI .