%0 Journal Article
%A R. P. Shepeleva
%T Critical frequencies of canonical systems, invariant with respect to time reversal, with periodic coefficients
%J Izvestiâ vysših učebnyh zavedenij. Matematika
%D 1980
%P 56-64
%N 9
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IVM_1980_9_a11/
%G ru
%F IVM_1980_9_a11