Kling, Thomas P. Geometric Analysis and Gravitation, AEI-Golm, MPI for Gravitational Physics, Max Planck Society;
9809037v1.pdf (Preprint), 406KB
prd59-124002.pdf (Publisher version), 303KB
Kling, T. P., & Newman, E. T. (1999). Null cones in Schwarzschild geometry. Physical Review D, 59(12): 124002. doi:10.1103/PhysRevD.59.124002.