TY  - JOUR
AU  - J. W. Heidel
TI  - Periodic solutions of $x" + f(x)x'^{2n} + g(x) = 0$ with arbitrarily large period
JO  - Annales Polonici Mathematici
PY  - 1970
SP  - 343
EP  - 348
VL  - 24
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/ap-24-3-343-348/
DO  - 10.4064/ap-24-3-343-348
LA  - en
ID  - 10_4064_ap_24_3_343_348
ER  -