%0 Journal Article
%A D.V. Dekov
%T HNN extensions of semigroups.
%J Semigroup forum
%D 1994
%P 83-88
%V 49
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1994__49_2_135336/
%F SF_1994__49_2_135336