@article{05629310, title = {Existence of periodic and almost periodic solutions of abstract retarded functional difference equations in phase spaces.}, journal = {Advances in Difference Equations [electronic only]}, volume = {2009}, year = {2009}, doi = {10.1155/2009/380568}, zbl = {1177.39017}, language = {en}, url = {http://dml.mathdoc.fr/item/05629310} }
Vidal, Claudio. Existence of periodic and almost periodic solutions of abstract retarded functional difference equations in phase spaces.. Advances in Difference Equations [electronic only], Tome 2009 (2009) . doi : 10.1155/2009/380568. http://gdmltest.u-ga.fr/item/05629310/