@article{DAN_1992_323_3_a9,
     author = {V. A. Malyshev},
     title = {Differential inequalities and the {Hadamard} conjecture},
     journal = {Doklady Akademii Nauk},
     pages = {420--422},
     publisher = {mathdoc},
     volume = {323},
     number = {3},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1992_323_3_a9/}
}