%0 Journal Article %A D.A. Jackson %T On the invariance of small overlap hypotheses. %J Semigroup forum %D 1991 %P 299-304 %V 43 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/SF_1991__43_3_135117/ %F SF_1991__43_3_135117