%0 Journal Article
%A John N. Mather
%T Concavity of the Lagrangian for quasi-periodic orbits.
%J Commentarii mathematici Helvetici
%D 1982
%P 356-376
%V 57
%I mathdoc
%U http://geodesic.mathdoc.fr/item/CMH_1982__57_139912/
%F CMH_1982__57_139912