@article{10_4064_sm184_2_1,
     author = {Shangquan Bu and Yi Fang},
     title = {Periodic solutions for second order integro-differential
equations with infinite delay in {Banach} spaces},
     journal = {Studia Mathematica},
     pages = {103--119},
     year = {2008},
     volume = {184},
     number = {2},
     doi = {10.4064/sm184-2-1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm184-2-1/}
}