%0 Journal Article
%A F. Knowles
%T A characterization of a class of semigroups.
%J Semigroup forum
%D 1974
%P 42-49
%V 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1974__6_133958/
%F SF_1974__6_133958