@article{05038330, title = {Construction of upper and lower solutions for singular discrete initial and boundary value problems via inequality theory.}, journal = {Advances in Difference Equations [electronic only]}, volume = {2005}, year = {2005}, pages = {205-214}, doi = {10.1155/ADE.2005.205}, zbl = {1103.39021}, language = {en}, url = {http://dml.mathdoc.fr/item/05038330} }
Lü, Haishen; O'Regan, Donal. Construction of upper and lower solutions for singular discrete initial and boundary value problems via inequality theory.. Advances in Difference Equations [electronic only], Tome 2005 (2005) pp. 205-214. doi : 10.1155/ADE.2005.205. http://gdmltest.u-ga.fr/item/05038330/