%0 Journal Article
%A Peter M. Gruber
%T Only ellipsoids have caustics.
%J Mathematische Annalen
%D 1995
%P 185-194
%V 303
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MAN_1995__303_4_165364/
%F MAN_1995__303_4_165364