@article{05602037,
title = {The method of lower and upper solutions for periodic and anti-periodic difference equations.},
journal = {ETNA. Electronic Transactions on Numerical Analysis [electronic only]},
volume = {26},
year = {2007},
pages = {13-25},
zbl = {1171.39301},
language = {en},
url = {http://dml.mathdoc.fr/item/05602037}
}
Cabada, Alberto. The method of lower and upper solutions for periodic and anti-periodic difference equations.. ETNA. Electronic Transactions on Numerical Analysis [electronic only], Tome 26 (2007) pp. 13-25. http://gdmltest.u-ga.fr/item/05602037/