G. W. Gibbons, 1977, Phys. Rev. D, 15, 2752, 10.1103/PhysRevD.15.2752
S. W. Hawking, 1975, Commun. Math. Phys., 43, 199, 10.1007/BF02345020
P. Gilkey, 1975, J. Diff. Geom., 10, 601, 10.4310/jdg/1214433164
S. W. Hawking, 1977, Commun. Math. Phys., 55, 133, 10.1007/BF01626516
F. A. Berezin, 1966, The Method of Second Quantization
B. Zumino, 1975, Nucl. Phys., B89, 535, 10.1016/0550-3213(75)90194-7
G. W. Gibbons, 1978, Nucl. Phys., B138, 141, 10.1016/0550-3213(78)90161-X
M. Duff, 1976, Nucl. Phys., B111, 45
L. S. Brown, 1977, Phys. Rev. D, 16, 1712, 10.1103/PhysRevD.16.1712
L. S. Brown, 1977, Phys. Rev. D, 15, 1469, 10.1103/PhysRevD.15.1469
R. Hagedorn, 1973, Cargèse Lectures in Physics
S. W. Hawking, 1977, Phys. Lett., 60A, 81, 10.1016/0375-9601(77)90386-3