%0 Journal Article
%A Juan Jorge Schäffer
%T Linear Difference Equations: Closedness of Covariant Sequences.
%J Mathematische Annalen
%D 1970
%P 69-76
%V 187
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MAN_1970__187_162005/
%F MAN_1970__187_162005