Allen, Bruce Observational Relativity and Cosmology, AEI-Hannover, MPI for Gravitational Physics, Max Planck Society;
nuclpb292-813.pdf (Publisher version), 2MB
Allen, B., & Turyn, M. (1987). An evaluation of the graviton propagator in de sitter space. Nuclear Physics B, 292, 813-852. doi:10.1016/0550-3213(87)90672-9.