1. M. Gimple and B.A. Auld. 6, edited by D.O. Thompson and D.E. Chimenti ( Plenum Press, New York, 1987 ).
2. M. Gimple and B.A. Auld, in Review of Progress in Quantitative NDE Vol. 7, edited by D.O. Thompson and D.E. Chimenti ( Plenum Press, New York, 1988 ), p. 50.
3. P.R. Heyliger, ibid, p 501.
4. P.J. Shull, ibid, p 517.
5. M.C. Zaretsky, L. Mougyad, and J.R. Melcher, IEEE Trans. Elec. Insul. 23, 897 (1988).