1. Determination of the electrical characteristics of deep layers of the Earth's core;Tikhonov;Dokl. Akad. Nauk SSSR,1950
2. Phase difference of earth currents induced by the changes of the earth's magnetic field;Kato;Sci. Rep. Tohoku Univ.,1950
3. Phase difference of earth currents induced by the changes of the earth's magnetic field;Kato;Sci. Rep. Tohoku Univ.,1950
4. Basic theory of the magneto-telluric method;Cagniard;Geophysics,1953
5. Systems of differential equations containing a parameter;Tikhonov;Mat. Sb.,1950