%0 Journal Article
%A Katsumi Nomizu
%A Kentaro Yano
%T On Circles and Spheres in Riemannian Geometry.
%J Mathematische Annalen
%D 1974
%P 163-170
%V 210
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MAN_1974__210_162616/
%F MAN_1974__210_162616