1. York, J. W. (1973).J. Math. Phys.,14, 456–464.
2. O Murchadha, N., and York, J. W. (1974).Phys. Rev. D,10, 428–436.
3. Misner, C. W., Thorne, K. S., and Wheeler, J. A. (1973).Gravitation (San Francisco, W. H. Freeman), Chapter 21.
4. Bowen, J. M., and York, J. W. (1979), “Cauchy Data on Spacelike Hypersurfaces with Spherical Inversion Symmetry,” to be published.