@article{02107690,
title = {The method of lower and upper solutions for some fourth-order equations.},
journal = {JIPAM. Journal of Inequalities in Pure \& Applied Mathematics [electronic only]},
volume = {5},
year = {2004},
zbl = {1063.34010},
language = {en},
url = {http://dml.mathdoc.fr/item/02107690}
}
Bai, Zhanbing; Ge, Weigao; Wang, Yifu. The method of lower and upper solutions for some fourth-order equations.. JIPAM. Journal of Inequalities in Pure & Applied Mathematics [electronic only], Tome 5 (2004) . http://gdmltest.u-ga.fr/item/02107690/