Very extensive references are provided by John D. Barrow and Frank J. Tipler, The Anthropic Cosmological Principle (Oxford: Clarendon Press, 1986), by John Leslie, Physical Cosmology and Philosophy, ed. John Leslie (New York: Macmillan Publishing Company, 1990), and by George F. Ellis, Before the Beginning: Cosmology Explained (New York: Boyars/Bowerdean, 1993). For a helpful survey and analysis see Southgate, Deane-Drummond, et al., God, Humanity and the Cosmos, C. 3 Section E.