@article{GDZPPN002195739,
title = {Stable closed orbits in plane autonomous dynamical systems.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {310},
year = {1979},
pages = {136-139},
zbl = {0395.34054},
url = {http://dml.mathdoc.fr/item/GDZPPN002195739}
}
Erle, Dieter. Stable closed orbits in plane autonomous dynamical systems.. Journal für die reine und angewandte Mathematik, Tome 310 (1979) pp. 136-139. http://gdmltest.u-ga.fr/item/GDZPPN002195739/