1. Boulware, D. G.: 1992, ?Quantum Field Theory in Spaces with Closed Timelike Curves?,Physical Review D 46, 4421?4441.
2. Earman, J.: 1993, ?The Cosmic Censorship Hypothesis?, in J. Earman, A. I. Janis, G. Massey, and N. Rescher (eds.),Philosophical Problems of the Internal and External Worlds: Essays On the Philosophy of Adolf Grünbaum, University of Pittsburgh Press, Pittsburgh, Pennsylvania.
3. Earman, J.: 1995, ?Recent Work on Time Travel?, in S. Savitt (ed.),Time's Arrow Today, Cambridge University Press, Cambridge, in press.
4. Friedman, J. L., Papastantiou, N. J., and Simon, J. L.: 1992, ?Failure of Unitarity for Interacting Fields in Spacetimes with Closed Timelike Curves?,Physical Review D 46, 4456?4476.
5. Geroch, R. P.: 1967, ?Topology in General Relativity?,Journal of Mathematical Physics 8, 782?786.