@article{GMJ_2003__10_2_50854,
     author = {Saker, S. H.},
     title = {Oscillation theorems of nonlinear difference equations of second order.},
     journal = {Georgian mathematical journal},
     pages = {343--352},
     year = {2003},
     volume = {10},
     number = {2},
     zbl = {1042.39004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/GMJ_2003__10_2_50854/}
}