@article{EJDE_2013__2013__a110,
     author = {Qi,  Yunsong and Yu,  Jinwei},
     title = {Oscillation criteria for fourth-order nonlinear delay dynamic equations},
     journal = {Electronic journal of differential equations},
     year = {2013},
     volume = {2013},
     zbl = {1290.34112},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2013__2013__a110/}
}