%0 Journal Article
%A V. V. Rybakov
%T A criterion for admissibility of inference rules in modal and
%J Doklady Akademii Nauk
%D 1985
%P 538-541
%V 284
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1985_284_3_a5/
%G ru
%F DAN_1985_284_3_a5