     With regard to the paper, the 3 references that I would add are
[GHJT] Maximum Determinant Completions, W. Glunt, T. Hayden, C. R.
Johnson,
       and P. Tarazaga, in press.
[JK] Principal Submatrices, Geometric Multiplicities, and Structured 
     Eigenvectors, C. R. Johnson and B. Kroschel, SIMAX 16 (1995),
1004-1012.
[JT] Approximate Semidefinite Matrices in a Subspace, C. R. Johnson and
P.
     Tarazaga, in manuscript.

