@article{05676021,
title = {An optimal existence theorem for positive solutions of a four-point boundary value problem.},
journal = {Electronic Journal of Differential Equations (EJDE) [electronic only]},
volume = {2009},
year = {2009},
zbl = {1193.34033},
language = {en},
url = {http://dml.mathdoc.fr/item/05676021}
}
Kwong, Man Kam; Wong, James S.W. An optimal existence theorem for positive solutions of a four-point boundary value problem.. Electronic Journal of Differential Equations (EJDE) [electronic only], Tome 2009 (2009) . http://gdmltest.u-ga.fr/item/05676021/