@article{DAN_1992_327_1_a3,
     author = {M. I. Tramov},
     title = {Oscillatory properties of linear differential equations with},
     journal = {Doklady Akademii Nauk},
     pages = {25--31},
     publisher = {mathdoc},
     volume = {327},
     number = {1},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1992_327_1_a3/}
}