@article{1250777600,
author = {Mizohata, Sigeru and Yamaguti, Masaya},
title = {On the Existence of Periodic Solutions of the Non-linear Differential Equation, $\ddot{x}+a(x) \cdot \dot{x}+\varphi (x)=p(t)$},
journal = {Mem. College Sci. Univ. Kyoto Ser. A Math.},
volume = {27},
number = {2},
year = {1952},
pages = { 109-113},
language = {en},
url = {http://dml.mathdoc.fr/item/1250777600}
}
Mizohata, Sigeru; Yamaguti, Masaya. On the Existence of Periodic Solutions of the Non-linear Differential Equation, $\ddot{x}+a(x) \cdot \dot{x}+\varphi (x)=p(t)$. Mem. College Sci. Univ. Kyoto Ser. A Math., Tome 27 (1952) no. 2, pp. 109-113. http://gdmltest.u-ga.fr/item/1250777600/