Ag. Kulikovskii et Yi. Sveshnikova, RIEMANN WAVES IN AN ELASTIC MEDIUM WITH SMALL ANISOTROPY, Journal of applied mathematics and mechanics, 57(3), 1993, pp. 493-502
Riemann waves in an arbitrary elastic medium with small anisotropy of
arbitrary form on the wave front plane are considered. The variation o
f the wave quantities is not assumed to be small. The principal attent
ion is devoted to situations in which the presence of small anisotropy
leads to qualitative modifications of the relations between the wave
quantities and determines the tendency of the waves to break.