Helioseismological inverse problem: sound speed in the solar interior

The asymptotic technique for the reconstruction of the sound speed distribution in solar interior from the observational frequencies of the five-minute oscillations is described. The significant improvement of the efficiency of reconstruction of the structure of the central solar regions is achieved due to the inclusion of the effects of self-gravitation into the asymptotic theory and due to the general improvement of the inversion technique. The results of the inversion of the experimental data are discussed