edited by G. W. Gibbons, S. W. Hawking, S. T.C. Siklos Gibbons, G. W. Hawking, S. W. Siklos, S. T. C. text Cambridge Cambridge University Press c1982 monographic 480 p. : ill. Universe Astronomy QB981 .N9 1982 0521253497 0521316774 UOEL 00 20150409150052.0