  We come back to the analytical solution of the standard transfer problem in a
stellar atmosphere. It consists in solving the radiative transfer equation in a
homogeneous and isothermal plane-parallel atmosphere, with light scattering
taken as isotropic and monochromatic. The literature on the subject is reviewed
and the existing solution in a finite slab is improved thanks to the
introduction of non classical auxiliary functions. Eleven-figure tables of the
solution are given for typical values of the input parameters currently met in
stellar atmospheres.
