@article{DAN_1973_210_2_a1,
     author = {R. G. Koplatadze},
     title = {The existence of oscillatory solutions of second-order nonlinear differential equations with retarded argument},
     journal = {Doklady Akademii Nauk},
     pages = {260--262},
     publisher = {mathdoc},
     volume = {210},
     number = {2},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1973_210_2_a1/}
}