  The explicit semiclassical treatment of logarithmic perturbation theory for
the bound-state problem within the framework of the Dirac equation is
developed. Avoiding disadvantages of the standard approach in the description
of exited states, new handy recursion formulae with the same simple form both
for ground and exited states have been obtained. As an example, the
perturbation expansions for the energy eigenvalues for the Yukawa potential
containing the vector part as well as the scalar component are considered.
