@article{DE_1981_17_4_a2,
     author = {I. V. Kamenev},
     title = {V.\,A.~Kondrat'ev's theorem on the distribution of zeros of solutions of a second-order linear differential equation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {598--603},
     publisher = {mathdoc},
     volume = {17},
     number = {4},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1981_17_4_a2/}
}