  A classical 3-D thermoviscoelastic system of Kelvin-Voigt type is considered.
The existence and uniqueness of a global regular solution is proved without
small data assumption. The existence proof is based on the successive
approximation method. The crucial part constitute a priori estimates on an
arbitrary finite time interval, which are derived with the help of the theory
of anisotropic Sobolev spaces with a mixed norm.
