“…On a larger scale still inhomogeneous spacetimes have been used to model clusters of galaxies [Kantowski, 1969a], variations in the Hubble flow due to the supercluster [Mavrides, 1977], the evolution of cosmic voids [Sato, 1984, Hausman et al, 1983, Bonnor and Chamorro, 1990and 1991, the observed distribution of galaxies and simple hierarchical models of the universe [Bonnor, 1972, Wesson, 1978, Wesson, 1979, Ribeiro, 1992a.…”