%0 Journal Article
%A V. P. Orevkov
%T Three ways of recognizing essential formulas in sequents
%J Zapiski Nauchnykh Seminarov POMI
%D 1979
%P 163-175
%V 88
%I mathdoc
%U http://geodesic.mathdoc.fr/item/ZNSL_1979_88_a11/
%G ru
%F ZNSL_1979_88_a11