@article{00735697, title = {Existence principles for second order nonresonant boundary value problems.}, journal = {Journal of Applied Mathematics and Stochastic Analysis}, volume = {7}, year = {1994}, pages = {487-507}, doi = {10.1155/S1048953394000389}, zbl = {0819.34019}, language = {en}, url = {http://dml.mathdoc.fr/item/00735697} }
O'Regan, Donal. Existence principles for second order nonresonant boundary value problems.. Journal of Applied Mathematics and Stochastic Analysis, Tome 7 (1994) pp. 487-507. doi : 10.1155/S1048953394000389. http://gdmltest.u-ga.fr/item/00735697/