%0 Journal Article
%A A. L. Likhtarnikov
%A V. A. Yakubovich
%T The frequency theorem for continuous one-parameter semigroups
%J Izvestiya. Mathematics 
%D 1977
%P 849-864
%V 11
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM2_1977_11_4_a7/
%G en
%F IM2_1977_11_4_a7