@article{1077469038,
author = {Cronin, Jane},
title = {The number of periodic solutions of non-autonomous systems},
journal = {Duke Math. J.},
volume = {27},
number = {1},
year = {1960},
pages = { 183-193},
language = {en},
url = {http://dml.mathdoc.fr/item/1077469038}
}
Cronin, Jane. The number of periodic solutions of non-autonomous systems. Duke Math. J., Tome 27 (1960) no. 1, pp. 183-193. http://gdmltest.u-ga.fr/item/1077469038/