@article{JNSA_2016_9_4_a8,
     author = {Ren, Zhiguo and Li, Jie and Shi, Haiping},
     title = {Existence of periodic solutions for second-order nonlinear difference equations },
     journal = {Journal of nonlinear sciences and its applications},
     pages = {1505-1514},
     publisher = {mathdoc},
     volume = {9},
     number = {4},
     year = {2016},
     doi = {10.22436/jnsa.009.04.09},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.22436/jnsa.009.04.09/}
}