%0 Journal Article
%A Gruska, Jozef
%T On star height hierarchies of context-free languages
%J Kybernetika
%D 1973
%P 231-236
%V 9
%N 4
%U http://geodesic.mathdoc.fr/item/KYB_1973_9_4_a0/
%G en
%F KYB_1973_9_4_a0