%0 Journal Article
%A Krajíček, Jan
%T Speed-up for propositional Frege systems via generalizations of proofs
%J Commentationes Mathematicae Universitatis Carolinae
%D 1989
%P 137-140
%V 30
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/CMUC_1989__30_1_a16/
%G en
%F CMUC_1989__30_1_a16