@article{05237423, title = {Multiple nonnegative solutions for BVPs of fourth-order difference equations.}, journal = {Advances in Difference Equations [electronic only]}, volume = {2006}, year = {2006}, doi = {10.1155/ADE/2006/89585}, zbl = {1139.39306}, language = {en}, url = {http://dml.mathdoc.fr/item/05237423} }
Sun, Jian-Ping. Multiple nonnegative solutions for BVPs of fourth-order difference equations.. Advances in Difference Equations [electronic only], Tome 2006 (2006) . doi : 10.1155/ADE/2006/89585. http://gdmltest.u-ga.fr/item/05237423/