@article{DAN_1987_295_4_a8,
     author = {E. A. Novikov and L. A. Yumatova},
     title = {Some methods for solving ordinary differential equations that are},
     journal = {Doklady Akademii Nauk},
     pages = {809--812},
     year = {1987},
     volume = {295},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1987_295_4_a8/}
}