TY  - JOUR
AU  - Klaus Schmitt
TI  - Periodic Solutions of Nonlinear Second Order Differential Equations.
JO  - Mathematische Zeitschrift
PY  - 1967
SP  - 200
EP  - 207
VL  - 98
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZ_1967__98_170745/
ID  - MZ_1967__98_170745
ER  -