1. J Schaffner-Bielich, J. Phys. G31, S561 (2005)
2. A R Bodmer, Phys. Rev. D4, 1601 (1971)
3. H Terazawa, INS-Report-338, University of Tokyo (1979)
4. E Witten, Phys. Rev. D30, 272 (1984)
5. R Xu, in Proceedings of the 2005 Lake Hanas International Pulsar Symposium, astro-ph/0512519