@article{DE_1967_3_3_a15,
     author = {A. I. Perov},
     title = {Bounded solutions of differential equations of second order},
     journal = {Differencialʹnye uravneni\^a},
     pages = {524--528},
     publisher = {mathdoc},
     volume = {3},
     number = {3},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1967_3_3_a15/}
}