Allen, Bruce Observational Relativity and Cosmology, AEI-Hannover, MPI for Gravitational Physics, Max Planck Society;
nuclpb287-743.pdf (Verlagsversion), 602KB
Allen, B. (1987). The graviton propagator in homogeneous and isotropic spacetimes. Nuclear Physics B, 287, 743-756. doi:10.1016/0550-3213(87)90126-X.