1. S. W. Hawking and G. F. R. Ellis,The Large Scale Structure of Space–Time(Cambridge University Press, Cambridge, 1973).
2. C. J. S. Clarke,The Analysis of Space–Time Singularities, Cambridge Lecture Notes in Physics (Cambridge University Press, Cambridge, 1993), Vol, 1.
3. Singular space-times
4. F. Tipler, C. J. S. Clarke, and G. F. R. Ellis, inGeneral Relativity and Gravitation, edited by A. Held (Plenum, New York, 1980), Vol. 2, p. 87.
5. Space‐time extensions I