%0 Journal Article
%A P. Sarnak
%A R. Osserman
%T A new curvature invariant and entropy of geodesic flow.
%J Inventiones mathematicae
%D 1984
%P 455-462
%V 77
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM_1984__77_143155/
%F IM_1984__77_143155