1. I B Zel’dovich and I D Novikov Relativistic Astrophysics, 2: The Structure and Evolution of the Universe (Chicago: University of Chicago Press) (1971)
2. W Misner, K S Thorne and J A Wheeler Gravitation (San Francisco: Freeman) (1973)
3. M J Rees The Very Early Universe (Cambridge: Cambridge University Press) G W Gibbons, S W Hawking and S Siklas (1983)
4. S Weinberg Gravitation and Cosmology (New York: Wiley) (1972)
5. H R Miller and P J Witta Active Galactic Nuclei (Berlin: Springer) (1987)