1. Bruzek, A: 1967, in J. Xanthakis (ed.), Solar Physics (Interscience), p. 414.
2. Canfield, R.C., Cheng, C.-C., Dere, K.P., Dulk, G.A., McLean, D.J., Robinson, R.D., Schmahl, E.J., and Schoolman, S.A.: 1980, in P.A. Sturrock (ed.), Solar Flares (Colorado), p. 451.
3. Donnelly, R.F.: 1971, Solar Physics 20, 188.
4. Hundhausen, A.J.: 1972, Coronal Expansion and the Solar Wind (Springer, New York).
5. HXRBS Team: 1982, private communication.