@article{EJDE_2000__2000__a200,
     author = {Elabbasy, El M. and Hegazi, A.S. and Saker, S.H.},
     title = {Oscillation of solutions to delay differential equations with positiv and negative coefficients},
     journal = {Electronic Journal of Differential Equations},
     publisher = {mathdoc},
     volume = {2000},
     year = {2000},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2000__2000__a200/}
}