%0 Journal Article
%A L. P. Zhil'tsova
%T Algorithmic complexity of problems of optimal alphabetical coding for context-free languages
%J Diskretnaya Matematika
%D 1989
%P 38-51
%V 1
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DM_1989_1_2_a3/
%G ru
%F DM_1989_1_2_a3