1. General references: Zirker, J. B. (ed.): 1977, Coronal Holes and High Speed Wind Streams (Colorado Univ. Press, Boulder).
2. Hundhausen, A. J.: 1972, Coronal Expansion and Solar Wind (Springer-Verlag, New York).
3. Withbroe, G. L. and Noyes, R. W.: 1978, Ann. Rev. Astro. Ap. 16, p. 363.
4. Gosling, J. T., Asbridge, J. R., Bame, S. J. and Feldman, W. C.: 1976, J. Geophys. Res. 81, p. 5061.
5. Feldman, W. C., Asbridge, J. R., Bame, S. J. and Gosling, J. T.: 1977, in “The Solar Output and its Variation,” O. R. White (ed.), p. 351 (Colorado Association Univ. Press, Boulder).