1. see for example collected papers in these Proceedings.
2. G.A.D. Briggs, “Acoustic Microscopy”, Oxford University Press, Oxford, 1992.
3. J.-P. Monchalin, IEEE Trans. UFFC-33 (1986) 485.
4. L.W. Kessler, Proc. 18th Symp. Acoustical Imaging (1991). Eds. H. Lee and G. Wade, Plenum Press, New York and London (1992).
5. H. Heil, J. Wesner, and W. Grill, J. Appl. Phys. 64,1939 (1988).