General relativity and gravitation, 1989 : proceedings of the 12th international conference on general relativity and gravitation, University of Colorado at Boulder, July 2-8, 1989 /
International Conference on General Relativity and Gravitation(12th :1989 :University of Colorado)
Ashby, Neil.
Bartlett, David F.
Wyss, Walter.
Cambridge : Cambridge University Press,
1990.
General relativity (Physics)
Gravitation.