1. Athay, R. G.: 1963, Astrophys. J. 138, 680.
2. Athay, R. G.: 1970, Solar Phys. 11, 347.
3. Athay, R. G. and Canfield, R. C.: 1969, Astrophys. J. 156, 695.
4. Athay, R. G. and Canfield, R.C.: 1970, in H. G. Groth and P. Wellmann (eds.), Extended Atmosphere Stars, NBS Special Publ. 332, Washington.
5. Athay, R. G. and Lites, B. W.: 1972, Astrophys. J. 176, 809.