@article{01230055,
title = {On the existence of a periodic solution of a nonlinear ordinary differential equation.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {21},
year = {1998},
pages = {767-774},
doi = {10.1155/S0161171298001070},
zbl = {0923.34046},
language = {en},
url = {http://dml.mathdoc.fr/item/01230055}
}
Chu, Hsin; Ding, Sunhong. On the existence of a periodic solution of a nonlinear ordinary differential equation.. International Journal of Mathematics and Mathematical Sciences, Tome 21 (1998) pp. 767-774. doi : 10.1155/S0161171298001070. http://gdmltest.u-ga.fr/item/01230055/