International School of Physics "Enrico Fermi.", Società italiana di fisica, & Ehlers, J. (1979). Isolated gravitating systems in general relativity, Varenna on Lake Como, Villa Monastero, 28th June-10th July 1976. North-Holland Pub. Co..

International School of Physics "Enrico Fermi.", Società italiana di fisica, and Jürgen Ehlers. Isolated Gravitating Systems in General Relativity, Varenna on Lake Como, Villa Monastero, 28th June-10th July 1976. Amsterdam ; New York: North-Holland Pub. Co., 1979.

International School of Physics "Enrico Fermi.", et al. Isolated Gravitating Systems in General Relativity, Varenna on Lake Como, Villa Monastero, 28th June-10th July 1976. North-Holland Pub. Co., 1979.