@article{00590306, title = {The method of lower and upper solutions for }, journal = {Journal of Applied Mathematics and Stochastic Analysis}, volume = {7}, year = {1994}, pages = {33-47}, doi = {10.1155/S1048953394000043}, zbl = {0801.34026}, language = {en}, url = {http://dml.mathdoc.fr/item/00590306} }
Cabada, Alberto. The method of lower and upper solutions for . Journal of Applied Mathematics and Stochastic Analysis, Tome 7 (1994) pp. 33-47. doi : 10.1155/S1048953394000043. http://gdmltest.u-ga.fr/item/00590306/