D. Landau and E. M. Lifshitz, Theory of Elasticity Pergamon, 1986.

D. Goddard, P. R. Soc, . London, and . Ser, 16 A word of caution is useful here. As shown in the theoretical analysis 25 the functional form of the effective compressibility has no reason to be a power law. This representation is only a convenient way to emphasize non-Hertzian behaviors, and the 1/4 " exponent " should not be taken too seriously, 1990.

. Ishimaru, Wave Propagation and Scattering in Random Media IEEE, 1997.

. Flandrin, Time-Frequency/Time-Scale Analysis Academic, J. Acoust. Soc. Am, vol.81, issue.36, 1998.

P. Auger, P. Flandrin, O. Gonçalves, and . Lemoine, Timefrequency toolbox, 1995. The toolbox and its tutorial may be downloaded at http://tftb.nongnu.org/. We refer the reader to this tutorial for the details on the signal processing