%0 Journal Article
%A Dieter Lutz
%T On bounded time-dependent perturbations of operator cosine functions.
%J Aequationes mathematicae
%D 1981
%P 197-203
%V 23
%I mathdoc
%U http://geodesic.mathdoc.fr/item/AM2_1981__23_136910/
%F AM2_1981__23_136910