%0 Journal Article
%A S. Ts. Akopyan
%A V. N. Zharkov
%A V. M. Lyubimov
%T The perturbation theory for Earth torsional oscillation. Second approximation
%J Doklady Akademii Nauk
%D 1972
%P 596-599
%V 204
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1972_204_3_a19/
%G ru
%F DAN_1972_204_3_a19