%0 Journal Article
%A E.M. Norris
%T Union preserving homomorphisms of semigroups of closed relations.
%J Semigroup forum
%D 1977
%P 169-180
%V 15
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1977__15_134247/
%F SF_1977__15_134247