@article{MZM_1975_18_1_a6,
     author = {I. V. Kamenev},
     title = {Nonoscillation criteria for solutions of a second-order linear differential equation},
     journal = {Matemati\v{c}eskie zametki},
     pages = {51--56},
     publisher = {mathdoc},
     volume = {18},
     number = {1},
     year = {1975},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1975_18_1_a6/}
}