1. Arnett, W. D.: 1973, in D. N. Schramm and W. D. Arnett (eds.),Explosive Nucleosynthesis, University of Texas Press, Austin, p. 236.
2. Cox, J. P. and Giuli, R. T.: 1968,Stellar Structure, Gordon and Breach, New York, p. 891.
3. De Gr�ve, J. P.: 1976, Ph.D. thesis, Vrije Universiteit Brussel.
4. De Gr�ve, J. P. and de Loore, C.: 1976,Astrophys. Space Sci. 43, 35.
5. De Gr�ve, J. P., de Loore, C., and Sutantyo, W.: 1975,Astrophys. Space Sci. 38, 301.