1. Withbroe G.L. (1988), The temperature, mass and energy flow in the corona and inner solar wind, Astroph. Journ., 325, 442–467
2. Waldmeier M. (1971), The solar corona in the eleven-year cycle, Physics of the Solar Corona (Proceedings of NATO ASI held at Athens, 6–17 September 1970), ed. C.J. Macris, Reidel, Dordrecht, 130–139
3. Structure de la couronne solaire;S Koutchmy,1986
4. Koutchmy S. and Loucif M.L. (1989), Solar cycle varations of coronal structures, Astron. Astroph. Suppl. Ser., 77, 45–66
5. Schuster A. (1879), On the polarisation of the solar corona, Monthly Notices of the R.A.S., 40, 35–57