%0 Journal Article
%A H. Cohen
%T Bands on trees.
%J Semigroup forum
%D 1989
%P 59-64
%V 39
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1989__39_2_134974/
%F SF_1989__39_2_134974