@article{urn:eudml:doc:38728, title = {Upper and lower solutions for first order problems with nonlinear boundary conditions.}, journal = {Extracta Mathematicae}, volume = {18}, year = {2003}, pages = {153-160}, zbl = {1086.34509}, mrnumber = {MR2002443}, language = {en}, url = {http://dml.mathdoc.fr/item/urn:eudml:doc:38728} }
Franco, Daniel; Nieto, Juan J.; O'Regan, Donal. Upper and lower solutions for first order problems with nonlinear boundary conditions.. Extracta Mathematicae, Tome 18 (2003) pp. 153-160. http://gdmltest.u-ga.fr/item/urn:eudml:doc:38728/