@article{DE_1970_6_9_a20,
     author = {I. V. Kamenev},
     title = {The oscillatoriness of the solutions of a second order nonlinear equation with a sign-variable coefficient},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1718--1721},
     publisher = {mathdoc},
     volume = {6},
     number = {9},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1970_6_9_a20/}
}