The neutral delay difference equations of second order with positive and negative coefficients , n = 0,1,2,... studied sufficient condition existence positive solution equation obtained
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-am31-1-2, author = {Wen-Xian Lin}, title = {On the existence of positive solutions of second order neutral difference equations}, journal = {Applicationes Mathematicae}, volume = {31}, year = {2004}, pages = {5-11}, zbl = {1059.39006}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-am31-1-2} }
Wen-Xian Lin. On the existence of positive solutions of second order neutral difference equations. Applicationes Mathematicae, Tome 31 (2004) pp. 5-11. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-am31-1-2/