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2. Bondi H . 1964 a N ature Lond. 202 275*.
3. Bondi H . 19646 Proc. Roy. Soc. A (In th e press).
4. General Relativistic Fluid Spheres
5. E ddington A. S. 1930 The mathematical theory of relativity p. 121. Cambridge U niversity Press. E d d in g to n 's rem arks h ad a g reat influence on other w riters. See for exam ple Curtis A. R . 1950 Proc. Roy. Soc. A 200 248 where th e identification of T and the particle density is tak en for granted.