@article{DAN_1987_296_3_a1,
     author = {M. Gera},
     title = {Some conditions for oscillation of a third-order linear differential equation},
     journal = {Doklady Akademii Nauk},
     pages = {525--528},
     year = {1987},
     volume = {296},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1987_296_3_a1/}
}