  Solutions of nonlinear acoustic equations describing propagation of strong
sound pulses with account of curvature of wave fronts in multi-dimensional
geometry are obtained from simple physical considerations. The form of these
solutions suggests ansatz suitable for finding solutions of much more general
equations of Khokhlov-Zabolotskaya type. General method is illustrated by an
example of nonlinear sound pulse focused in one transverse direction and
defocused in the other direction.
