%0 Journal Article
%A J. Goldstein
%A c. Radin
%A R. Showalter
%T Convergence rates of ergodic limits for semigroups and cosine functions.
%J Semigroup forum
%D 1978
%P 89-96
%V 16
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SF_1978__16_134276/
%F SF_1978__16_134276