@article{SMJ2_2004_30_1_a5,
     author = {Elabbasy, E. and Hassan, T.},
     title = {Oscillation {Criteria} for {First} {Order} {Delay} {Differential} {Equations}},
     journal = {Serdica Mathematical Journal},
     pages = {71--86},
     publisher = {mathdoc},
     volume = {30},
     number = {1},
     year = {2004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SMJ2_2004_30_1_a5/}
}