@article{DAN_1989_305_1_a11,
     author = {Tran Duc Van and Ha Huy Bang},
     title = {Solvability of infinite-order nonlinear differential equations in},
     journal = {Doklady Akademii Nauk},
     pages = {48--51},
     publisher = {mathdoc},
     volume = {305},
     number = {1},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1989_305_1_a11/}
}