@article{DE_1973_9_12_a3,
     author = {S. N. Olekhnik},
     title = {The oscillatory nature of the solutions of a certain system of second order ordinary differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2146--2151},
     publisher = {mathdoc},
     volume = {9},
     number = {12},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_12_a3/}
}