%0 Journal Article
%A Frank Hansen
%T Means and Concave Products of Positive Semi-Definite Matrices.
%J Mathematische Annalen
%D 1983
%P 119-128
%V 264
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MAN_1983__264_163774/
%F MAN_1983__264_163774