%0 Journal Article
%A Niemelä, Lassi
%T On the directability of automata
%J Kybernetika
%D 1989
%P 419-421
%V 25
%N 5
%I mathdoc
%U http://geodesic.mathdoc.fr/item/KYB_1989__25_5_a6/
%G en
%F KYB_1989__25_5_a6