%0 Journal Article
%A Klaus Schmitt
%T Periodic Solutions of Nonlinear Second Order Differential Equations.
%J Mathematische Zeitschrift
%D 1967
%P 200-207
%V 98
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MZ_1967__98_170745/
%F MZ_1967__98_170745