%0 Journal Article
%A R. M. Capocelli
%T On some subsemigroups of a free semigroup.
%J Semigroup forum
%D 1977
%P 125-136
%V 15
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1977__15_134243/
%F SF_1977__15_134243