1. Arge, C.N.: 2004, In: AGU Fall Meeting, SH52A-02.
2. Arge, C.N., Hildner, E., Pizzo, V.J., Harvey, J.W.: 2002, J. Geophys. Res. 107(A10), SSH 16-1.
3. Balthasar, H.: 1984, Solar Phys. 93, 219.
4. Berger, T.E., Lites, B.W.: 2003, Solar Phys. 213, 213.
5. Bruls, J.H.M.J., Lites, B.W., Murphy, G.A.: 1991, In: November, L.J. (ed.) Solar Polarimetry, National Solar Observatory, Sacramento Peak, 444.