@article{SMJ2_2008_34_4_a1,
     author = {Hassan, Taher S.},
     title = {Interval {Oscillation} for {Second} {Order} {Nonlinear} {Differential} {Equations} with a {Damping} {Term}},
     journal = {Serdica Mathematical Journal},
     pages = {715--732},
     publisher = {mathdoc},
     volume = {34},
     number = {4},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SMJ2_2008_34_4_a1/}
}