1. Bray, R.J., Loughhead, R.E. and Durrant, C.J. : 1984, The Solar Granulation 2nd Edition, Cambridge University Press.
2. Macris, C.J.: 1979, Astron. Astrophys. 78, 186.
3. Muller, R.: 1977, Solar Physics, 52, 249.
4. Muller, R. and Keil, S.L.: 1983, Solar Physics, 87, 243.
5. Muller, R. : 1099, 27 COSPAR General Assembly, Helsinki, Symp. n? 12, Variability of solar granulation