@article{DE_1971_7_11_a23,
     author = {B. I. Medvedev},
     title = {An asymptotic solution of ordinary second order differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2111--2114},
     publisher = {mathdoc},
     volume = {7},
     number = {11},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1971_7_11_a23/}
}