%0 Journal Article
%A È. I. Grudo
%T Bifurcation equations for the existence of periodic solutions of periodic Pfaffian systems
%J Differencialʹnye uravneniâ
%D 1985
%P 1857-1867
%V 21
%N 11
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1985_21_11_a2/
%G ru
%F DE_1985_21_11_a2