@article{bwmeta1.element.desklight-0d5bccfb-5250-4349-927b-f40bba015920,
author = {F. H. Szafraniec},
title = {Note on the existence of periodic solutions of a second order differential equation},
journal = {Annales Polonici Mathematici},
volume = {21},
year = {1969},
pages = {305-307},
zbl = {0194.12101},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.desklight-0d5bccfb-5250-4349-927b-f40bba015920}
}
F. H. Szafraniec. Note on the existence of periodic solutions of a second order differential equation. Annales Polonici Mathematici, Tome 21 (1969) pp. 305-307. http://gdmltest.u-ga.fr/item/bwmeta1.element.desklight-0d5bccfb-5250-4349-927b-f40bba015920/