@article{EJDE_2012__2012__a37,
     author = {Yankson, Ernest},
     title = {Positive periodic solutions for second-order neutral differential equations with functional delay},
     journal = {Electronic Journal of Differential Equations},
     publisher = {mathdoc},
     volume = {2012},
     year = {2012},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2012__2012__a37/}
}