1. Rees MJ. The very early universe. Gibbons GW, Hawking SW, Siklas S, editors. Cambridge: Cambridge University Press; 1983.
2. Misner W, Throne KS, Wheeler JA. Gravitation. San Francisco: Freeman; 1973; p. 763.
3. Miller HR, Witter PJ. Active galactic nuclei. Berlin: Springer. 1987; p. 202.
4. Pulsar Electrodynamics
5. Theory of pulsar magnetospheres