%0 Journal Article
%A S. R. Aleksanyan
%T On proof normal forms for some systems of classical propositional logic
%J Proceedings of the Yerevan State University. Physical and mathematical sciences
%D 2007
%P 39-45
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/UZERU_2007_1_a4/
%G hy
%F UZERU_2007_1_a4