%0 Journal Article
%A Gruska, Jozef
%T A note on $\varepsilon$-rules in context-free grammars
%J Kybernetika
%D 1975
%P -31
%V 11
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/KYB_1975__11_1_a2/
%G en
%F KYB_1975__11_1_a2