%0 Journal Article
%A G.B. Preston
%T Schützenberger groups of ...-classes in the semigroup of all binary relations on a set.
%J Semigroup forum
%D 1974
%P 260-262
%V 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1974__6_133982/
%F SF_1974__6_133982