%0 Journal Article
%A T.E. Nordahl
%T Commutative semigroups whose proper subsemigroups are projective.
%J Semigroup forum
%D 1974
%P 35-41
%V 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1974__6_133957/
%F SF_1974__6_133957