@article{EJDE_2010__2010__a15,
     author = {Du,  Bo and Wang,  Xiaojing},
     title = {Periodic solutions for a second-order neutral differential equation with variable parameter and multiple deviating arguments},
     journal = {Electronic journal of differential equations},
     year = {2010},
     volume = {2010},
     zbl = {1200.34076},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2010__2010__a15/}
}