@article{DAN_1989_307_1_a9,
     author = {N. V. Khusnutdinova},
     title = {On the structure of the domain of degeneration of a system of},
     journal = {Doklady Akademii Nauk},
     pages = {45--49},
     publisher = {mathdoc},
     volume = {307},
     number = {1},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1989_307_1_a9/}
}