%0 Journal Article
%A V. P. Orevkov
%T Two unsolvable classes of formulas of classical predicate calculus
%J Zapiski Nauchnykh Seminarov POMI
%D 1968
%P 202-210
%V 8
%I mathdoc
%U http://geodesic.mathdoc.fr/item/ZNSL_1968_8_a22/
%G ru
%F ZNSL_1968_8_a22