@article{05847801,
title = {Existence of positive solutions of nonlinear second-order periodic boundary value problems.},
journal = {Boundary Value Problems [electronic only]},
volume = {2010},
year = {2010},
doi = {10.1155/2010/626054},
zbl = {1219.34055},
language = {en},
url = {http://dml.mathdoc.fr/item/05847801}
}
Ma, Ruyun; Gao, Chenghua; Chen, Ruipeng. Existence of positive solutions of nonlinear second-order periodic boundary value problems.. Boundary Value Problems [electronic only], Tome 2010 (2010) . doi : 10.1155/2010/626054. http://gdmltest.u-ga.fr/item/05847801/