@article{SMJ2_1997_23_1_a0,
     author = {Elabbasy, E.},
     title = {Oscillation {Theorems} for {Perturbed} {Second} {Order} {Nonlinear} {Differential} {Equations} with {Damping}},
     journal = {Serdica Mathematical Journal},
     pages = {1--14},
     publisher = {mathdoc},
     volume = {23},
     number = {1},
     year = {1997},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SMJ2_1997_23_1_a0/}
}