%0 Journal Article
%A Amha Tume Lisan
%T Free groups in ßN which miss the minimal ideal.
%J Semigroup forum
%D 1988
%P 233-240
%V 37
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1988__37_1_134927/
%F SF_1988__37_1_134927