1. Bertschinger, E. 1988, submitted to Ap.J.
2. Bertschinger, E., and Meiksin, A. 1986, Ap.J.(Letters), 806, L1.
3. Canizares, C. R. 1988, these proceedings.
4. Chevalier, R. A. 1987, Ap.J., 818, 66.
5. Mathews, W. G., and Bregman, J. N. 1978, Ap.J., 224,308.