1. Abraham, Z. and Iben, I., Jr. Astrophys.J., 1971, 170, 157.
2. Brodsky, M. A. and Vorontsov, S. V., these proceedings.
3. Christensen-Dalsgaard, J. Mon.Not.Roy.Astron.Soc., 1985.
4. Libbrecht, K. G. and Zirin, H. Submitted to Astrophys.J.,1985.
5. Pidatella, R. M. and Stix, M. Astron.Astrophys., 1986, 157, 338.