%0 Journal Article
%A C . Vachuska
%A P. Vachuska
%T The bicyclic semigroup has F4*.
%J Semigroup forum
%D 1993
%P 133-134
%V 47
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1993__47_2_135264/
%F SF_1993__47_2_135264