%0 Journal Article
%A K.D. jr. Magill
%A S. Yamamuro
%T Union and symmetry preserving homomorphisms of semigroups of closed relations.
%J Semigroup forum
%D 1971
%P 168-172
%V 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1971__3_133859/
%F SF_1971__3_133859