@article{KJM_2009_32_1_a5,
     author = {Yuji Liu},
     title = {Periodic solutions of fourth-order functional differential equations with $p${-Laplacian}},
     journal = {Kragujevac Journal of Mathematics},
     pages = {61 - 73},
     publisher = {mathdoc},
     volume = {32},
     number = {1},
     year = {2009},
     zbl = {1199.34352},
     url = {http://geodesic.mathdoc.fr/item/KJM_2009_32_1_a5/}
}